diff --git a/.cursor-plugin/plugin.json b/.cursor-plugin/plugin.json index fff94ee..cd30201 100644 --- a/.cursor-plugin/plugin.json +++ b/.cursor-plugin/plugin.json @@ -144,6 +144,8 @@ "showcase/campfire", "showcase/market-stall", "showcase/street-lantern", - "showcase/treasure-chest" + "showcase/treasure-chest", + "showcase/terrain-scatter", + "showcase/fence-kit" ] } diff --git a/AGENTS.md b/AGENTS.md index d920173..5fef89b 100644 --- a/AGENTS.md +++ b/AGENTS.md @@ -21,7 +21,7 @@ classifies it as a `cursor-plugin`. This is content the AI loads when the user asks Blender questions or works on Blender add-ons in Cursor or Claude Code. The content base is 16 skills, 9 rules, 3 templates, 27 snippets, 59 -examples, and 7 showcase pieces (counts are CI-enforced against README.md +examples, and 9 showcase pieces (counts are CI-enforced against README.md and the manifest). The full inventory tables and per-item purposes live in `CLAUDE.md`. Example anatomy and authoring rules: copy `examples/bmesh-gear/`; showcase conventions: `showcase/README.md`. The render look is specified diff --git a/CLAUDE.md b/CLAUDE.md index 6e9cb0e..dbb9054 100644 --- a/CLAUDE.md +++ b/CLAUDE.md @@ -22,7 +22,7 @@ rules/.mdc - Anti-pattern rules, 9 total templates// - Starter projects, 3 total snippets/.py - Standalone code patterns, 27 total examples// - Runnable smoke-gated examples, 59 total (+ gallery.json) -showcase// - Budget-conformance props, 7 pieces (sibling of examples/; see showcase/README.md) +showcase// - Budget-conformance props, 9 pieces (sibling of examples/; see showcase/README.md) scripts/build_gallery.py - Regenerates docs/gallery/ from examples/gallery.json + showcase/gallery.json scripts/site/ - Vendored landing-page build (Jinja2) docs/gallery/ - Committed generated gallery pages + hero renders diff --git a/README.md b/README.md index 60d9673..fa01acd 100644 --- a/README.md +++ b/README.md @@ -18,7 +18,7 @@

- 16 skills  •  9 rules  •  3 templates  •  27 snippets  •  59 examples  •  7 showcase pieces + 16 skills  •  9 rules  •  3 templates  •  27 snippets  •  59 examples  •  9 showcase pieces

@@ -37,7 +37,7 @@ ## Overview -This repository ships **16 skills, 9 rules, 3 templates, 27 snippets, 59 examples, and 7 showcase pieces** for Blender Python development targeting Blender 5.2 LTS (current stable) with Blender 4.5 LTS fallback support. Blender 5.1 is prior stable. +This repository ships **16 skills, 9 rules, 3 templates, 27 snippets, 59 examples, and 9 showcase pieces** for Blender Python development targeting Blender 5.2 LTS (current stable) with Blender 4.5 LTS fallback support. Blender 5.1 is prior stable. The content is consumed by AI coding agents (Cursor, Claude Code, any MCP-capable client) when working on Blender add-ons, geometry nodes scripts, batch pipelines, or animation tooling. There is no build step. Edit the markdown and Python files directly. @@ -82,6 +82,8 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show Market stall: a timber frame with post feet, slatted counter, rafters, and a striped awning on a dark studio floor, warm wedge on the back wall Street lantern: an iron post with brass collars, a braced arm, and a muntined amber cage on a dark studio floor Treasure chest: a slatted wooden chest with iron bands, corner brackets, and an open lid on a dark studio floor +Terrain scatter: a Geometry Nodes dirt hill tile with bevelled masonry rocks on a dark studio floor +Fence kit: a timber post-and-rail section with pyramidal caps, iron shoes and straps on a dark studio floor [`shipping-crate`](showcase/shipping-crate/) — procedural crate through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets. Falsifier `--skip-decimate` exits 9. @@ -97,6 +99,10 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show [`treasure-chest`](showcase/treasure-chest/) — procedural slatted chest with iron bands, corner brackets, and an open lid through the same pipeline. Falsifier `--skip-decimate` exits 9. +[`terrain-scatter`](showcase/terrain-scatter/) — Geometry Nodes hill tile with bevelled masonry scatter through the same pipeline. Falsifier `--skip-decimate` exits 9. + +[`fence-kit`](showcase/fence-kit/) — procedural post-and-rail fence section through the same pipeline. Falsifier `--skip-decimate` exits 9. + ## Examples Runnable, smoke-gated demos live in [`examples/`](examples/) — each is executed headless on diff --git a/ROADMAP.md b/ROADMAP.md index be5c2be..e056f05 100644 --- a/ROADMAP.md +++ b/ROADMAP.md @@ -111,11 +111,11 @@ Not committed; target list for the next content version. (v0.3.0 shipped the smo - ~~Wooden barrel showcase~~ **SHIPPED** as `showcase/wooden-barrel/` — bulged staves, four iron hoops, lid heads; `--skip-decimate` exits 9 on the LOD1 ratio band - ~~Campfire showcase~~ **SHIPPED** as `showcase/campfire/` — two-course fire ring, log tripod; `--skip-decimate` exits 9 on the LOD1 ratio band - ~~Market stall showcase~~ **SHIPPED** as `showcase/market-stall/` — timber frame, slatted counter, striped awning; `--skip-decimate` exits 9 on the LOD1 ratio band -- Procedural terrain or landscape showcase using Geometry Nodes scatter +- ~~Procedural terrain or landscape showcase using Geometry Nodes scatter~~ **SHIPPED** as `showcase/terrain-scatter/` — GN sine-hill Mesh Grid, Index-jittered Instance-on-Points scatter replaced with bevelled masonry; `--skip-decimate` exits 9 on the LOD1 ratio band - ~~Hero prop with a more complex silhouette (lantern or treasure chest) as a second showcase piece~~ **SHIPPED** as `showcase/street-lantern/` and `showcase/treasure-chest/` — hanging iron lantern with muntined amber cage; slatted chest with iron bands and an open lid; `--skip-decimate` exits 9 on the LOD1 ratio band - Wrought-iron park bench (slatted seat, scrolled legs) as a game-prop showcase piece - Wooden wheelbarrow (staved tray, single wheel, handles) as a game-prop showcase piece -- Small modular kit showcase on recognizable geometry (`modular-kit-snap` contract) +- ~~Small modular kit showcase on recognizable geometry (`modular-kit-snap` contract)~~ **SHIPPED** as `showcase/fence-kit/` — tiling post-and-rail section (AABB X is the tile width; does not re-witness the snap contract); `--skip-decimate` exits 9 on the LOD1 ratio band - ~~Custom ID-property delete witness~~ **SHIPPED** as `examples/cross-version-property-delete/` — IDs built via `bpy.data.objects.new` (not `active_object`); `property_unset` is TypeError and leaves the key; `del` removes it on 4.5 LTS and 5.x - ~~USD export evaluation_mode witness~~ **SHIPPED** as `examples/usd-export-evaluation-mode/` — probed `wm.usd_export` on CI Linux portables 5.2.1 (`9e2066aef7ef`) and 4.5.13 (`daeeeca98fb0`); TESSELLATE+VIEWPORT 26/24, TESSELLATE+RENDER 98/96; BEST_MATCH writes the 8-vert catmullClark cage so the mode is silent diff --git a/docs/gallery/assets/fence-kit-hero.webp b/docs/gallery/assets/fence-kit-hero.webp new file mode 100644 index 0000000..590a532 Binary files /dev/null and b/docs/gallery/assets/fence-kit-hero.webp differ diff --git a/docs/gallery/assets/terrain-scatter-hero.webp b/docs/gallery/assets/terrain-scatter-hero.webp new file mode 100644 index 0000000..a60c903 Binary files /dev/null and b/docs/gallery/assets/terrain-scatter-hero.webp differ diff --git a/docs/gallery/campfire/index.html b/docs/gallery/campfire/index.html index e8303ae..7790d34 100644 --- a/docs/gallery/campfire/index.html +++ b/docs/gallery/campfire/index.html @@ -264,7 +264,7 @@

campfire

Composes skills mesh-editing-and-bmesh, bake-high-to-low, depsgraph-and-evaluated-data, engine-export-presets, and snippets bake_normal_high_to_low.py, setup_bake_target_image.py, lod_chain.py / decimate_to_budget.py, convex_hull_collider.py, export_preset_unity.py (helpers copied, not imported as a package).

Budgets

Declared as named constants; every gate recomputes from the mesh, materials, UVs, evaluated LOD, collider, or export file.

-

| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) | | --- | --- | --- | | Base triangles | 3500–3750 | 3616 / 3616 / 3616 | | LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | | LOD2 ratio | 0.10–0.35 of base | 0.2196 / 0.2196 / 0.2196 | | Materials | exactly 3 distinct, ≥24 wood faces, ≥8 ash faces | 3 slots, 100 wood, 48 ash | | UVs | in 0..1, AABB overlap ≤ 1e-5 | in range, overlap 0 | | Outer AABB | (0.789, 0.789, 0.410) m ± 0.01 | (0.7891, 0.7891, 0.4099), zmin 0 | | Collider tris | ≤ 320 | 254 | | Export | written, size > 0 | 273604 / 273604 / 273596 bytes |

+

| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) | | --- | --- | --- | | Base triangles | 3500–3750 | 3616 / 3616 / 3616 | | LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | | LOD2 ratio | 0.10–0.35 of base | 0.2196 / 0.2196 / 0.2196 | | Materials | exactly 3 distinct, ≥24 wood faces, ≥8 ash faces | 3 slots, 100 wood, 48 ash | | UVs | in 0..1, AABB overlap ≤ 1e-5 | in range, overlap 0 | | Outer AABB | (0.789, 0.789, 0.410) m ± 0.01 | (0.7891, 0.7891, 0.4094), zmin 0 | | Collider tris | ≤ 320 | 254 | | Export | written, size > 0 | 273604 / 273604 / 273596 bytes |

DECIMATE COLLAPSE triangle counts are not guaranteed identical across series — the gate is a ratio band, not an exact count. This mesh happened to match on 4.5.11 / 5.1.2 / 5.2.1. Bake pixels are stochastic; the gate is has_data plus operator FINISHED, not byte-identity. Construction uses no RNG. glTF byte size differs by a few bytes across series.

--skip-decimate skips the LOD DECIMATE stage so LOD1 ratio is 1.0 and exit 9 fires. That is the named budget the falsifier violates.

Run

diff --git a/docs/gallery/fence-kit/index.html b/docs/gallery/fence-kit/index.html new file mode 100644 index 0000000..a2d76d3 --- /dev/null +++ b/docs/gallery/fence-kit/index.html @@ -0,0 +1,1036 @@ + + + + + + fence-kit — Examples — Blender Developer Tools + + + + + + + + + + + + + + + + + +
+ Examples Gallery +
+ GitHub +
+
+
+

fence-kit

+

A procedural post-and-rail fence section through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.

+
+
+ +

Rendered headless by the example itself — click to zoom.

+
witnesses Recomputed: 1212 tris, two materials with 120 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.642×0.157×1.235 m, LOD ratios in band, convex collider 62 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.
+
+ 
blender --background --python showcase/fence-kit/fence_kit.py --
+ +
+
+

A showcase piece, not an example. Procedural post-and-rail fence section (two posts, pyramidal caps, three rails, kickboard, brace, iron shoes and straps) then the shipped pipeline: unique-cell UVs, Cycles high-to-low normal bake, LOD chain, convex collider, Unity glTF export.

+

It asserts budget conformance of the generated result. It does not witness an API contract. "It rendered without error" is not a check. AABB X is the tile width so adjacent copies meet; this piece does not re-witness the modular-kit-snap snap contract.

+

Composes skills mesh-editing-and-bmesh, bake-high-to-low, depsgraph-and-evaluated-data, engine-export-presets, and snippets bake_normal_high_to_low.py, setup_bake_target_image.py, lod_chain.py / decimate_to_budget.py, convex_hull_collider.py, export_preset_unity.py (helpers copied, not imported as a package).

+

Budgets

+

Declared as named constants; every gate recomputes from the mesh, materials, UVs, evaluated LOD, collider, or export file.

+

| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) | | --- | --- | --- | | Base triangles | 1160–1280 | 1212 / 1212 / 1212 | | LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | | LOD2 ratio | 0.10–0.35 of base | 0.2195 / 0.2195 / 0.2079 | | Materials | exactly 2 distinct, ≥24 metal faces | 2 slots, 120 metal | | UVs | in 0..1, AABB overlap ≤ 1e-5 | in range, overlap 0 | | Outer AABB | (1.642, 0.157, 1.235) m ± 0.01 | (1.6418, 0.1574, 1.2350), zmin 0 | | Collider tris | ≤ 96 | 62 | | Export | written, size > 0 | 93232 / 93232 / 93224 bytes |

+

DECIMATE COLLAPSE triangle counts are not identical across series — 5.2.1 is more aggressive on LOD2. The gate is a ratio band, not an exact count. Bake pixels are stochastic; the gate is has_data plus operator FINISHED, not byte-identity. Construction uses no RNG.

+

--skip-decimate skips the LOD DECIMATE stage so LOD1 ratio is 1.0 and exit 9 fires. That is the named budget the falsifier violates.

+

Run

+
blender --background --python fence_kit.py --
+blender --background --python fence_kit.py -- --skip-decimate
+blender --background --python fence_kit.py -- --output fence.png
+

Smoke does not pass --output or --skip-decimate.

+

Exit codes

+

File-local. 9 is a valid check code. 10 is reserved for gallery_framing.check_framing on the --output path.

+

| Code | Meaning | | --- | --- | | 0 | Success | | 1 | Uncaught exception (FATAL wrapper) | | 2 | argparse / usage | | 3 | Mesh did not build / no UV layer | | 4 | Base triangle count outside range | | 5 | Material count ≠ 2 distinct slots, or metal faces missing | | 6 | UVs outside 0..1 | | 7 | UV AABB overlap above tolerance | | 8 | World AABB off declared outer size | | 9 | LOD ratio band (--skip-decimate lands here) | | 10 | Framing gate (render path only) | | 11 | Collider triangle count above ceiling | | 12 | Bake did not finish or image has no data | | 13 | Export file missing or empty | | 14 | --output produced no file |

+
+
+

Source

+
+ showcase/fence-kit/fence_kit.py + View on GitHub → +
+ 
"""Game-ready post-and-rail fence kit — a showcase piece, not an example.
+
+Asserts budget conformance of a tiling timber fence section after
+composing shipped pipeline pieces: bmesh construction, UVs, two
+materials, high-to-low normal bake, LOD chain, convex collider,
+Unity glTF export.
+
+Budgets are declared below and recomputed from the generated result.
+They are not API-contract witnesses. ``--skip-decimate`` skips the LOD
+DECIMATE stage so the LOD-ratio budget fails.
+
+No RNG. Construction is closed-form. AABB X is the tile width so
+adjacent copies meet; this piece does not re-witness the modular-kit
+snap contract. DECIMATE COLLAPSE triangle counts are not byte-identical
+across Blender versions — the LOD gate is a ratio band, not an exact
+count.
+
+    blender --background --python fence_kit.py --
+    blender --background --python fence_kit.py -- --skip-decimate
+    blender --background --python fence_kit.py -- --output fence.png
+"""
+import argparse
+import math
+import os
+import sys
+import tempfile
+import traceback
+
+import bmesh
+import bpy
+from mathutils import Euler, Vector
+
+_REPO = os.path.abspath(
+    os.path.join(os.path.dirname(os.path.abspath(__file__)), os.pardir, os.pardir)
+)
+sys.path.insert(0, os.path.join(_REPO, "examples"))
+sys.dont_write_bytecode = True
+import gallery_framing  # noqa: E402
+
+TILE = 1.60
+POST_W = 0.110
+POST_H = 1.14
+CAP_H = 0.095
+RAIL_Y = 0.055
+RAIL_Z = 0.064
+RAIL_ZS = (0.30, 0.58, 0.86)
+KICK_Z = 0.125
+KICK_Y = 0.040
+BRACE_T = 0.042
+IRON_T = 0.016
+SHOE_H = 0.034
+SHOE_SCALE = 1.38
+
+BBOX_TOL = 0.01
+OUTER_SIZE = (1.642, 0.157, 1.235)
+BASE_TRIS_MIN = 1160
+BASE_TRIS_MAX = 1280
+LOD1_RATIO_MIN = 0.32
+LOD1_RATIO_MAX = 0.62
+LOD2_RATIO_MIN = 0.10
+LOD2_RATIO_MAX = 0.35
+LOD1_TARGET = 0.50
+LOD2_TARGET = 0.22
+MATERIAL_COUNT = 2
+UV_EPS = 1e-4
+UV_OVERLAP_MAX = 1e-5
+COLLIDER_TRIS_MAX = 96
+BAKE_RES = 256
+CAGE_EXTRUSION = 0.06
+METAL_FACES_MIN = 24
+
+WOOD_IDX = 0
+METAL_IDX = 1
+
+
+def eevee_engine_id():
+    return "BLENDER_EEVEE" if bpy.app.version >= (5, 0, 0) else "BLENDER_EEVEE_NEXT"
+
+
+def fail(msg, code):
+    print(f"ERROR: {msg}", file=sys.stderr)
+    return code
+
+
+def triangle_count(mesh):
+    mesh.calc_loop_triangles()
+    return len(mesh.loop_triangles)
+
+
+def evaluated_triangle_count(obj):
+    depsgraph = bpy.context.evaluated_depsgraph_get()
+    eval_obj = obj.evaluated_get(depsgraph)
+    eval_mesh = eval_obj.to_mesh()
+    try:
+        eval_mesh.calc_loop_triangles()
+        return len(eval_mesh.loop_triangles)
+    finally:
+        eval_obj.to_mesh_clear()
+
+
+def deselect_all():
+    for ob in list(bpy.context.view_layer.objects):
+        if ob is None:
+            continue
+        ob.select_set(False)
+
+
+def add_box(bm, loc, scale, mat_idx, euler=(0.0, 0.0, 0.0)):
+    geo = bmesh.ops.create_cube(bm, size=1.0)
+    verts = geo["verts"]
+    rot = Euler(euler).to_matrix()
+    origin = Vector(loc)
+    for v in verts:
+        p = Vector((v.co.x * scale[0], v.co.y * scale[1], v.co.z * scale[2]))
+        v.co = rot @ p + origin
+    faces = {f for v in verts for f in v.link_faces}
+    for f in faces:
+        f.material_index = mat_idx
+    return verts
+
+
+def add_cone(bm, loc, radius1, radius2, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)):
+    geo = bmesh.ops.create_cone(
+        bm,
+        cap_ends=True,
+        cap_tris=False,
+        segments=segments,
+        radius1=radius1,
+        radius2=radius2,
+        depth=depth,
+    )
+    verts = geo["verts"]
+    rot = Euler(euler).to_matrix()
+    origin = Vector(loc)
+    for v in verts:
+        v.co = rot @ v.co + origin
+    faces = {f for v in verts for f in v.link_faces}
+    for f in faces:
+        f.material_index = mat_idx
+    return verts
+
+
+def pack_uvs(bm, margin=0.08):
+    uv = bm.loops.layers.uv.new("UVMap")
+    faces = list(bm.faces)
+    n = len(faces)
+    cols = max(1, math.ceil(math.sqrt(n)))
+    rows = max(1, math.ceil(n / cols))
+    cell_w = 1.0 / cols
+    cell_h = 1.0 / rows
+    pad_u = margin * cell_w * 0.5
+    pad_v = margin * cell_h * 0.5
+    usable_w = cell_w - 2.0 * pad_u
+    usable_h = cell_h - 2.0 * pad_v
+    for i, face in enumerate(faces):
+        col = i % cols
+        row = i // cols
+        nrm = face.normal
+        ax = abs(nrm.x)
+        ay = abs(nrm.y)
+        az = abs(nrm.z)
+        coords = []
+        for loop in face.loops:
+            co = loop.vert.co
+            if az >= ax and az >= ay:
+                coords.append((co.x, co.y))
+            elif ax >= ay:
+                coords.append((co.y, co.z))
+            else:
+                coords.append((co.x, co.z))
+        xs = [c[0] for c in coords]
+        ys = [c[1] for c in coords]
+        minx, maxx = min(xs), max(xs)
+        miny, maxy = min(ys), max(ys)
+        dx = max(maxx - minx, 1e-8)
+        dy = max(maxy - miny, 1e-8)
+        origin_u = col * cell_w + pad_u
+        origin_v = row * cell_h + pad_v
+        for loop, (x, y) in zip(face.loops, coords):
+            loop[uv].uv = (
+                origin_u + (x - minx) / dx * usable_w,
+                origin_v + (y - miny) / dy * usable_h,
+            )
+
+
+def build_fence_mesh(name, bevel_offset, bevel_segments):
+    bm = bmesh.new()
+    try:
+        wood_verts = []
+        post_xs = (-(TILE / 2.0 - POST_W / 2.0), TILE / 2.0 - POST_W / 2.0)
+        for px in post_xs:
+            wood_verts.extend(
+                add_box(bm, (px, 0.0, POST_H / 2.0), (POST_W, POST_W, POST_H), WOOD_IDX)
+            )
+            wood_verts.extend(
+                add_cone(
+                    bm,
+                    (px, 0.0, POST_H + CAP_H / 2.0),
+                    POST_W * 0.72,
+                    0.010,
+                    CAP_H,
+                    4,
+                    WOOD_IDX,
+                    euler=(0.0, 0.0, math.pi / 4.0),
+                )
+            )
+
+        rail_len = TILE - POST_W * 0.18
+        for z in RAIL_ZS:
+            wood_verts.extend(
+                add_box(bm, (0.0, 0.0, z), (rail_len, RAIL_Y, RAIL_Z), WOOD_IDX)
+            )
+
+        wood_verts.extend(
+            add_box(
+                bm,
+                (0.0, 0.0, KICK_Z / 2.0),
+                (TILE - POST_W * 0.22, KICK_Y, KICK_Z),
+                WOOD_IDX,
+            )
+        )
+
+        span = TILE - POST_W
+        rise = RAIL_ZS[-1] - RAIL_ZS[0]
+        brace_len = math.hypot(span, rise)
+        brace_ang = math.atan2(rise, span)
+        wood_verts.extend(
+            add_box(
+                bm,
+                (0.0, -POST_W * 0.55, (RAIL_ZS[0] + RAIL_ZS[-1]) / 2.0),
+                (brace_len, BRACE_T, BRACE_T),
+                WOOD_IDX,
+                euler=(0.0, -brace_ang, 0.0),
+            )
+        )
+
+        if bevel_offset > 0.0:
+            edges = list({e for v in wood_verts for e in v.link_edges})
+            bmesh.ops.bevel(
+                bm,
+                geom=edges,
+                offset=bevel_offset,
+                segments=bevel_segments,
+                profile=0.5,
+                affect="EDGES",
+                clamp_overlap=True,
+            )
+
+        for px in post_xs:
+            add_box(
+                bm,
+                (px, 0.0, SHOE_H / 2.0),
+                (POST_W * SHOE_SCALE, POST_W * SHOE_SCALE, SHOE_H),
+                METAL_IDX,
+            )
+            sign = 1.0 if px > 0.0 else -1.0
+            for z in RAIL_ZS:
+                add_box(
+                    bm,
+                    (px, POST_W / 2.0 + IRON_T / 2.0, z),
+                    (POST_W * 0.88, IRON_T, RAIL_Z * 1.40),
+                    METAL_IDX,
+                )
+                add_box(
+                    bm,
+                    (px, -(POST_W / 2.0 + IRON_T / 2.0), z),
+                    (POST_W * 0.88, IRON_T, RAIL_Z * 1.40),
+                    METAL_IDX,
+                )
+                add_box(
+                    bm,
+                    (px + sign * (POST_W / 2.0 + IRON_T / 2.0), 0.0, z),
+                    (IRON_T, POST_W * 0.88, RAIL_Z * 1.40),
+                    METAL_IDX,
+                )
+
+        xs = [v.co.x for v in bm.verts]
+        ys = [v.co.y for v in bm.verts]
+        zs = [v.co.z for v in bm.verts]
+        cy = 0.5 * (min(ys) + max(ys))
+        zmin = min(zs)
+        for v in bm.verts:
+            v.co.y -= cy
+            v.co.z -= zmin
+            if v.co.z < 0.0:
+                v.co.z = 0.0
+
+        pack_uvs(bm)
+        bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces))
+        for face in bm.faces:
+            face.smooth = False
+        me = bpy.data.meshes.new(name)
+        bm.to_mesh(me)
+        me.update()
+        for poly in me.polygons:
+            poly.use_smooth = False
+    finally:
+        bm.free()
+    out = bpy.data.objects.new(name, me)
+    bpy.context.collection.objects.link(out)
+    return out
+
+
+def principled(name, color, metallic, roughness):
+    mat = bpy.data.materials.new(name)
+    mat.use_nodes = True
+    bsdf = mat.node_tree.nodes["Principled BSDF"]
+    bsdf.inputs["Base Color"].default_value = color
+    bsdf.inputs["Metallic"].default_value = metallic
+    bsdf.inputs["Roughness"].default_value = roughness
+    return mat
+
+
+def assign_slots(obj, wood, metal):
+    # Do not materials.clear() — that resets polygon material_index to 0
+    # on this Blender, which would drop metal faces onto wood.
+    mats = obj.data.materials
+    wanted = (wood, metal)
+    for i, mat in enumerate(wanted):
+        if i < len(mats):
+            mats[i] = mat
+        else:
+            mats.append(mat)
+
+
+def world_bbox(obj):
+    corners = [obj.matrix_world @ Vector(c) for c in obj.bound_box]
+    xs = [c.x for c in corners]
+    ys = [c.y for c in corners]
+    zs = [c.z for c in corners]
+    return (min(xs), min(ys), min(zs), max(xs), max(ys), max(zs))
+
+
+def uv_stats(mesh):
+    uv = mesh.uv_layers.active
+    if uv is None:
+        return 0.0, 0.0, 1.0, 1.0, 0, 1.0
+    data = uv.data
+    us = [loop.uv[0] for loop in data]
+    vs = [loop.uv[1] for loop in data]
+    aabbs = []
+    for poly in mesh.polygons:
+        pu = [data[i].uv[0] for i in poly.loop_indices]
+        pv = [data[i].uv[1] for i in poly.loop_indices]
+        aabbs.append((min(pu), min(pv), max(pu), max(pv)))
+    overlap = 0.0
+    for i in range(len(aabbs)):
+        a = aabbs[i]
+        for j in range(i + 1, len(aabbs)):
+            b = aabbs[j]
+            x0 = max(a[0], b[0])
+            y0 = max(a[1], b[1])
+            x1 = min(a[2], b[2])
+            y1 = min(a[3], b[3])
+            overlap += max(0.0, x1 - x0) * max(0.0, y1 - y0)
+    return min(us), min(vs), max(us), max(vs), overlap, len(aabbs)
+
+
+def make_lod(obj, name, ratio, skip_decimate):
+    mesh = obj.data.copy()
+    lod = bpy.data.objects.new(name, mesh)
+    lod.matrix_world = obj.matrix_world.copy()
+    bpy.context.scene.collection.objects.link(lod)
+    if not skip_decimate and 0.0 < ratio < 1.0:
+        mod = lod.modifiers.new("DecimateBudget", "DECIMATE")
+        mod.decimate_type = "COLLAPSE"
+        mod.ratio = ratio
+    return lod
+
+
+def convex_hull_collider(obj, name):
+    mesh = bpy.data.meshes.new(name)
+    bm = bmesh.new()
+    try:
+        bm.from_mesh(obj.data)
+        result = bmesh.ops.convex_hull(bm, input=list(bm.verts))
+        interior = result.get("geom_interior") or []
+        unused = result.get("geom_unused") or []
+        if interior:
+            bmesh.ops.delete(bm, geom=interior, context="VERTS")
+        if unused:
+            bmesh.ops.delete(bm, geom=unused, context="VERTS")
+        bm.to_mesh(mesh)
+        mesh.update()
+    finally:
+        bm.free()
+    collider = bpy.data.objects.new(name, mesh)
+    bpy.context.collection.objects.link(collider)
+    collider.matrix_world = obj.matrix_world.copy()
+    return collider
+
+
+def setup_bake_image(obj, target_mat, size=BAKE_RES):
+    if not obj.data.uv_layers:
+        return None, None
+    img = bpy.data.images.new("FenceNrm", size, size, alpha=True, float_buffer=False)
+    img.colorspace_settings.name = "Non-Color"
+    nodes = target_mat.node_tree.nodes
+    tex = nodes.new("ShaderNodeTexImage")
+    tex.image = img
+    nodes.active = tex
+    tex.select = True
+    obj.active_material_index = WOOD_IDX
+    return img, tex
+
+
+def bake_normal(high, low):
+    scene = bpy.context.scene
+    scene.render.engine = "CYCLES"
+    scene.cycles.device = "CPU"
+    scene.cycles.samples = 1
+    scene.cycles.use_denoising = False
+    deselect_all()
+    high.select_set(True)
+    low.select_set(True)
+    bpy.context.view_layer.objects.active = low
+    return bpy.ops.object.bake(
+        type="NORMAL",
+        use_selected_to_active=True,
+        cage_extrusion=CAGE_EXTRUSION,
+        use_cage=False,
+        normal_space="TANGENT",
+        margin=4,
+        margin_type="ADJACENT_FACES",
+        use_clear=True,
+        target="IMAGE_TEXTURES",
+    )
+
+
+def export_unity(path, objects):
+    deselect_all()
+    for ob in objects:
+        ob.select_set(True)
+    bpy.context.view_layer.objects.active = objects[0]
+    bpy.ops.export_scene.gltf(
+        filepath=path,
+        use_selection=True,
+        export_yup=True,
+        export_apply=True,
+        export_draco_mesh_compression_enable=False,
+        export_animations=False,
+    )
+
+
+def check(skip_decimate):
+    bpy.ops.wm.read_factory_settings(use_empty=True)
+    low = build_fence_mesh("FenceLow", bevel_offset=0.006, bevel_segments=2)
+    high = build_fence_mesh("FenceHigh", bevel_offset=0.006, bevel_segments=4)
+    wood = principled("FenceWood", (0.46, 0.24, 0.08, 1.0), 0.0, 0.55)
+    metal = principled("FenceIron", (0.11, 0.115, 0.13, 1.0), 1.0, 0.28)
+    assign_slots(low, wood, metal)
+    assign_slots(high, wood, metal)
+
+    if low.data is None or len(low.data.polygons) < 6:
+        return fail("fence mesh did not build", 3), None, None, None, None, None
+
+    base_tris = triangle_count(low.data)
+    mats = [s for s in low.data.materials if s is not None]
+    nmat = len(mats)
+    distinct_mats = len({id(s) for s in mats})
+    idx_counts = {}
+    for poly in low.data.polygons:
+        idx_counts[poly.material_index] = idx_counts.get(poly.material_index, 0) + 1
+    print(f"measured mat_index_counts={idx_counts}")
+    u0, v0, u1, v1, overlap, nfaces = uv_stats(low.data)
+    bb = world_bbox(low)
+    size_x = bb[3] - bb[0]
+    size_y = bb[4] - bb[1]
+    size_z = bb[5] - bb[2]
+
+    img, tex = setup_bake_image(low, wood)
+    if img is None:
+        return fail("fence has no UV layer", 3), None, None, None, None, None
+    bake_result = bake_normal(high, low)
+
+    lod1 = make_lod(low, "FenceLOD1", LOD1_TARGET, skip_decimate)
+    lod2 = make_lod(low, "FenceLOD2", LOD2_TARGET, skip_decimate)
+    bpy.context.view_layer.update()
+    lod1_tris = evaluated_triangle_count(lod1)
+    lod2_tris = evaluated_triangle_count(lod2)
+    r1 = lod1_tris / base_tris if base_tris else 0.0
+    r2 = lod2_tris / base_tris if base_tris else 0.0
+
+    collider_src = build_fence_mesh("FenceColSrc", bevel_offset=0.0, bevel_segments=1)
+    collider = convex_hull_collider(collider_src, "FenceCollider")
+    bpy.data.objects.remove(collider_src, do_unlink=True)
+    col_tris = triangle_count(collider.data)
+
+    export_path = os.path.join(
+        tempfile.gettempdir(),
+        f"bdt_fence_kit_{os.getpid()}.glb",
+    )
+    if os.path.exists(export_path):
+        os.remove(export_path)
+    export_unity(export_path, [low, collider])
+    export_size = os.path.getsize(export_path) if os.path.isfile(export_path) else 0
+
+    print(f"blender={tuple(bpy.app.version)} skip_decimate={skip_decimate}")
+    print(
+        f"measured base_tris={base_tris} lod1_tris={lod1_tris} "
+        f"lod2_tris={lod2_tris} r1={r1:.4f} r2={r2:.4f}"
+    )
+    print(
+        f"measured nmat={nmat} uv=({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f}) "
+        f"overlap={overlap:.6f} nfaces={nfaces}"
+    )
+    print(
+        f"measured bbox=({size_x:.4f},{size_y:.4f},{size_z:.4f}) "
+        f"outer={OUTER_SIZE} zmin={bb[2]:.4f}"
+    )
+    print(
+        f"measured collider_tris={col_tris} bake={bake_result} "
+        f"bake_has_data={img.has_data} export_bytes={export_size}"
+    )
+
+    if not (BASE_TRIS_MIN <= base_tris <= BASE_TRIS_MAX):
+        return fail(
+            f"base tris {base_tris} not in [{BASE_TRIS_MIN}, {BASE_TRIS_MAX}]",
+            4,
+        ), None, None, None, None, None
+    if nmat != MATERIAL_COUNT or distinct_mats != MATERIAL_COUNT:
+        return fail(
+            f"material slots {nmat} distinct {distinct_mats} != {MATERIAL_COUNT}",
+            5,
+        ), None, None, None, None, None
+    if idx_counts.get(METAL_IDX, 0) < METAL_FACES_MIN:
+        return fail(
+            f"metal faces {idx_counts.get(METAL_IDX, 0)} < {METAL_FACES_MIN}",
+            5,
+        ), None, None, None, None, None
+    if u0 < -UV_EPS or v0 < -UV_EPS or u1 > 1.0 + UV_EPS or v1 > 1.0 + UV_EPS:
+        return fail(
+            f"UVs outside 0..1: ({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f})",
+            6,
+        ), None, None, None, None, None
+    if overlap > UV_OVERLAP_MAX:
+        return fail(
+            f"UV AABB overlap {overlap:.6f} > {UV_OVERLAP_MAX}",
+            7,
+        ), None, None, None, None, None
+    if (
+        abs(size_x - OUTER_SIZE[0]) > BBOX_TOL
+        or abs(size_y - OUTER_SIZE[1]) > BBOX_TOL
+        or abs(size_z - OUTER_SIZE[2]) > BBOX_TOL
+    ):
+        return fail(
+            f"bbox ({size_x:.4f},{size_y:.4f},{size_z:.4f}) "
+            f"off outer {OUTER_SIZE}",
+            8,
+        ), None, None, None, None, None
+    if not (LOD1_RATIO_MIN <= r1 <= LOD1_RATIO_MAX):
+        return fail(
+            f"LOD1 ratio {r1:.4f} not in [{LOD1_RATIO_MIN}, {LOD1_RATIO_MAX}] "
+            "(--skip-decimate is the designed fail)",
+            9,
+        ), None, None, None, None, None
+    if not (LOD2_RATIO_MIN <= r2 <= LOD2_RATIO_MAX):
+        return fail(
+            f"LOD2 ratio {r2:.4f} not in [{LOD2_RATIO_MIN}, {LOD2_RATIO_MAX}]",
+            9,
+        ), None, None, None, None, None
+    if col_tris > COLLIDER_TRIS_MAX:
+        return fail(
+            f"collider tris {col_tris} > {COLLIDER_TRIS_MAX}",
+            11,
+        ), None, None, None, None, None
+    if bake_result != {"FINISHED"} or not img.has_data:
+        return fail(
+            f"bake failed result={bake_result} has_data={img.has_data}",
+            12,
+        ), None, None, None, None, None
+    if export_size <= 0:
+        return fail("export file missing or empty", 13), None, None, None, None, None
+    return 0, low, high, wood, tex, collider
+
+
+def wire_normal(mat, tex):
+    nt = mat.node_tree
+    bsdf = nt.nodes["Principled BSDF"]
+    nrm = nt.nodes.new("ShaderNodeNormalMap")
+    nrm.inputs["Strength"].default_value = 1.0
+    nt.links.new(tex.outputs["Color"], nrm.inputs["Color"])
+    nt.links.new(nrm.outputs["Normal"], bsdf.inputs["Normal"])
+
+
+def render_still(low, wood, tex, path, engine):
+    scene = bpy.context.scene
+    wire_normal(wood, tex)
+    for ob in list(scene.objects):
+        if ob.type == "MESH" and ob != low:
+            ob.hide_render = True
+            ob.hide_viewport = True
+
+    low.rotation_euler.z = math.radians(-16.0)
+    low.rotation_euler.x = math.radians(2.0)
+
+    floor_me = bpy.data.meshes.new("Floor")
+    bm = bmesh.new()
+    try:
+        bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0)
+        bm.to_mesh(floor_me)
+    finally:
+        bm.free()
+    fmat = bpy.data.materials.new("Floor")
+    fmat.use_nodes = True
+    fb = fmat.node_tree.nodes["Principled BSDF"]
+    fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0)
+    fb.inputs["Roughness"].default_value = 0.7
+    floor_me.materials.append(fmat)
+    floor = bpy.data.objects.new("Floor", floor_me)
+    scene.collection.objects.link(floor)
+    wall = bpy.data.objects.new("Wall", floor_me.copy())
+    wall.location = (0.0, 8.5, 0.0)
+    wall.rotation_euler = (math.radians(90), 0.0, 0.0)
+    scene.collection.objects.link(wall)
+
+    world = bpy.data.worlds.new("World")
+    world.use_nodes = True
+    world.node_tree.nodes["Background"].inputs["Color"].default_value = (
+        0.02, 0.021, 0.025, 1.0,
+    )
+    scene.world = world
+
+    def light(name, loc, energy, size, col, rot):
+        ld = bpy.data.lights.new(name, "AREA")
+        ld.energy = energy
+        ld.size = size
+        ld.color = col
+        ob = bpy.data.objects.new(name, ld)
+        ob.location = loc
+        ob.rotation_euler = tuple(math.radians(a) for a in rot)
+        scene.collection.objects.link(ob)
+
+    light("Key", (-3.6, -5.0, 5.8), 680.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36))
+    light("Fill", (5.0, -3.6, 2.6), 48.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50))
+    light("Wedge", (2.4, 4.2, 4.1), 640.0, 5.5, (1.0, 0.70, 0.40), (-70, 0, 198))
+
+    cam_data = bpy.data.cameras.new("Cam")
+    cam_data.lens = 50.0
+    cam = bpy.data.objects.new("Cam", cam_data)
+    cam.location = (2.50, -3.46, 1.95)
+    scene.collection.objects.link(cam)
+    aim = bpy.data.objects.new("Aim", None)
+    aim.location = (0.0, 0.0, 0.58)
+    scene.collection.objects.link(aim)
+    con = cam.constraints.new("TRACK_TO")
+    con.target = aim
+    con.track_axis = "TRACK_NEGATIVE_Z"
+    con.up_axis = "UP_Y"
+    scene.camera = cam
+
+    scene.render.engine = "CYCLES" if engine == "cycles" else eevee_engine_id()
+    if engine == "cycles":
+        scene.cycles.samples = 32
+        scene.cycles.device = "CPU"
+    else:
+        try:
+            scene.eevee.taa_render_samples = 64
+        except AttributeError:
+            pass
+    scene.render.resolution_x = 1280
+    scene.render.resolution_y = 720
+    scene.render.image_settings.file_format = (
+        "WEBP" if path.lower().endswith(".webp") else "PNG"
+    )
+    if path.lower().endswith(".webp"):
+        scene.render.image_settings.quality = 90
+    scene.render.filepath = path
+    scene.view_settings.view_transform = "Standard"
+
+    fcode = gallery_framing.check_framing(
+        scene, cam, hero=[low], elements=[low], stage=[floor, wall],
+    )
+    if fcode:
+        return fcode
+    bpy.ops.render.render(write_still=True)
+    if not (os.path.exists(path) and os.path.getsize(path) > 0):
+        return fail("render produced no file", 14)
+    return 0
+
+
+def main():
+    argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []
+    p = argparse.ArgumentParser()
+    p.add_argument("--output", default=None)
+    p.add_argument("--engine", default="eevee", choices=("eevee", "cycles"))
+    p.add_argument(
+        "--skip-decimate",
+        action="store_true",
+        help="falsification: skip the LOD DECIMATE stage",
+    )
+    args = p.parse_args(argv)
+
+    code, low, _high, wood, tex, _col = check(args.skip_decimate)
+    if code:
+        return code
+    if args.output:
+        rcode = render_still(low, wood, tex, os.path.abspath(args.output), args.engine)
+        if rcode:
+            return rcode
+        print(f"rendered still {args.output}")
+    print("fence-kit OK")
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        sys.exit(main())
+    except Exception as e:
+        traceback.print_exc()
+        print(f"FATAL: {e}", file=sys.stderr)
+        sys.exit(1)
+
+
+
+ +
+
+ generated from examples/gallery.json + CC-BY-NC-ND-4.0 + exit 0 +
+
+ + + diff --git a/docs/gallery/index.html b/docs/gallery/index.html index 0133e33..63152c6 100644 --- a/docs/gallery/index.html +++ b/docs/gallery/index.html @@ -272,7 +272,7 @@

Examples Gallery

autocomplete="off" spellcheck="false" aria-label="Search examples" /> - 58 examples + 60 examples
@@ -962,6 +962,28 @@

treasure-chest

View example
+
+ + terrain-scatter — A Geometry Nodes hill tile with masonry scatter through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract. + +
+

terrain-scatter

+

A Geometry Nodes hill tile with masonry scatter through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.

+

witnesses Recomputed: 1194 tris, two materials with 486 stone faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.800×1.800×0.655 m, LOD ratios in band, convex collider 52 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.

+ View example +
+
+
+ + fence-kit — A procedural post-and-rail fence section through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract. + +
+

fence-kit

+

A procedural post-and-rail fence section through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.

+

witnesses Recomputed: 1212 tris, two materials with 120 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.642×0.157×1.235 m, LOD ratios in band, convex collider 62 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.

+ View example +
+
diff --git a/docs/gallery/terrain-scatter/index.html b/docs/gallery/terrain-scatter/index.html new file mode 100644 index 0000000..827bb59 --- /dev/null +++ b/docs/gallery/terrain-scatter/index.html @@ -0,0 +1,1212 @@ + + + + + + terrain-scatter — Examples — Blender Developer Tools + + + + + + + + + + + + + + + + + +
+ Examples Gallery +
+ GitHub +
+
+
+

terrain-scatter

+

A Geometry Nodes hill tile with masonry scatter through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.

+
+
+ +

Rendered headless by the example itself — click to zoom.

+
witnesses Recomputed: 1194 tris, two materials with 486 stone faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.800×1.800×0.655 m, LOD ratios in band, convex collider 52 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.
+
+ 
blender --background --python showcase/terrain-scatter/terrain_scatter.py --
+ +
+
+

A showcase piece, not an example. Geometry Nodes sine-hill Mesh Grid with an Index-jittered Instance-on-Points scatter, realized cubes replaced by bevelled masonry, then the shipped pipeline: unique-cell UVs, Cycles high-to-low normal bake, LOD chain, convex collider, Unity glTF export.

+

It asserts budget conformance of the generated result. It does not witness an API contract. "It rendered without error" is not a check.

+

Composes skills geometry-nodes-python, mesh-editing-and-bmesh, bake-high-to-low, depsgraph-and-evaluated-data, engine-export-presets, and snippets bake_normal_high_to_low.py, setup_bake_target_image.py, lod_chain.py / decimate_to_budget.py, convex_hull_collider.py, export_preset_unity.py (helpers copied, not imported as a package).

+

Budgets

+

Declared as named constants; every gate recomputes from the mesh, materials, UVs, evaluated LOD, collider, or export file.

+

| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) | | --- | --- | --- | | Base triangles | 1150–1250 | 1194 / 1194 / 1194 | | LOD1 ratio | 0.32–0.62 of base | 0.4992 / 0.4992 / 0.4992 | | LOD2 ratio | 0.10–0.35 of base | 0.2194 / 0.2194 / 0.2194 | | Materials | exactly 2 distinct, ≥24 stone faces | 2 slots, 486 stone | | UVs | in 0..1, AABB overlap ≤ 1e-5 | in range, overlap 0 | | Outer AABB | (1.800, 1.800, 0.655) m ± 0.01 | (1.8000, 1.8000, 0.6554), zmin 0 | | Collider tris | ≤ 80 | 52 | | Export | written, size > 0 | 90704 / 90704 / 90696 bytes |

+

DECIMATE COLLAPSE triangle counts are not guaranteed identical across series — the gate is a ratio band, not an exact count. This mesh happened to match on 4.5.11 / 5.1.2 / 5.2.1. Bake pixels are stochastic; the gate is has_data plus operator FINISHED, not byte-identity. Construction uses no RNG. glTF byte size may differ by a few bytes across series.

+

--skip-decimate skips the LOD DECIMATE stage so LOD1 ratio is 1.0 and exit 9 fires. That is the named budget the falsifier violates.

+

Run

+
blender --background --python terrain_scatter.py --
+blender --background --python terrain_scatter.py -- --skip-decimate
+blender --background --python terrain_scatter.py -- --output terrain.png
+

Smoke does not pass --output or --skip-decimate.

+

Exit codes

+

File-local. 9 is a valid check code. 10 is reserved for gallery_framing.check_framing on the --output path.

+

| Code | Meaning | | --- | --- | | 0 | Success | | 1 | Uncaught exception (FATAL wrapper) | | 2 | argparse / usage | | 3 | Mesh did not build / no UV layer | | 4 | Base triangle count outside range | | 5 | Material count ≠ 2 distinct slots, or stone faces missing | | 6 | UVs outside 0..1 | | 7 | UV AABB overlap above tolerance | | 8 | World AABB off declared outer size | | 9 | LOD ratio band (--skip-decimate lands here) | | 10 | Framing gate (render path only) | | 11 | Collider triangle count above ceiling | | 12 | Bake did not finish or image has no data | | 13 | Export file missing or empty | | 14 | --output produced no file |

+
+
+

Source

+
+ showcase/terrain-scatter/terrain_scatter.py + View on GitHub → +
+ 
"""Game-ready GN terrain scatter — a showcase piece, not an example.
+
+Asserts budget conformance of a Geometry Nodes hill grid with instanced
+masonry rocks after composing shipped pipeline pieces: GN construction,
+UVs, two materials, high-to-low normal bake, LOD chain, convex collider,
+Unity glTF export.
+
+Budgets are declared below and recomputed from the generated result.
+They are not API-contract witnesses. ``--skip-decimate`` skips the LOD
+DECIMATE stage so the LOD-ratio budget fails.
+
+No RNG. Hills are a closed-form sine product; scatter is an Index-jittered
+instance grid. Realized cubes are replaced with bevelled lumped boxes
+(campfire/well masonry, not icospheres). DECIMATE COLLAPSE triangle
+counts are not byte-identical across Blender versions — the LOD gate is
+a ratio band, not an exact count.
+
+    blender --background --python terrain_scatter.py --
+    blender --background --python terrain_scatter.py -- --skip-decimate
+    blender --background --python terrain_scatter.py -- --output terrain.png
+"""
+import argparse
+import math
+import os
+import sys
+import tempfile
+import traceback
+
+import bmesh
+import bpy
+from mathutils import Euler, Vector
+
+_REPO = os.path.abspath(
+    os.path.join(os.path.dirname(os.path.abspath(__file__)), os.pardir, os.pardir)
+)
+sys.path.insert(0, os.path.join(_REPO, "examples"))
+sys.dont_write_bytecode = True
+import gallery_framing  # noqa: E402
+
+PATCH = 1.80
+FREQ = 2.2
+AMP = 0.16
+ROCK_SIZE = (0.22, 0.17, 0.13)
+ROCK_GRID = 3
+ROCK_SPAN = 1.15
+SLAB_LIFT = 0.10
+
+BBOX_TOL = 0.01
+OUTER_SIZE = (1.800, 1.800, 0.655)
+BASE_TRIS_MIN = 1150
+BASE_TRIS_MAX = 1250
+LOD1_RATIO_MIN = 0.32
+LOD1_RATIO_MAX = 0.62
+LOD2_RATIO_MIN = 0.10
+LOD2_RATIO_MAX = 0.35
+LOD1_TARGET = 0.50
+LOD2_TARGET = 0.22
+MATERIAL_COUNT = 2
+UV_EPS = 1e-4
+UV_OVERLAP_MAX = 1e-5
+COLLIDER_TRIS_MAX = 80
+BAKE_RES = 256
+CAGE_EXTRUSION = 0.08
+STONE_FACES_MIN = 24
+
+DIRT_IDX = 0
+STONE_IDX = 1
+
+
+def eevee_engine_id():
+    return "BLENDER_EEVEE" if bpy.app.version >= (5, 0, 0) else "BLENDER_EEVEE_NEXT"
+
+
+def fail(msg, code):
+    print(f"ERROR: {msg}", file=sys.stderr)
+    return code
+
+
+def triangle_count(mesh):
+    mesh.calc_loop_triangles()
+    return len(mesh.loop_triangles)
+
+
+def evaluated_triangle_count(obj):
+    depsgraph = bpy.context.evaluated_depsgraph_get()
+    eval_obj = obj.evaluated_get(depsgraph)
+    eval_mesh = eval_obj.to_mesh()
+    try:
+        eval_mesh.calc_loop_triangles()
+        return len(eval_mesh.loop_triangles)
+    finally:
+        eval_obj.to_mesh_clear()
+
+
+def deselect_all():
+    for ob in list(bpy.context.view_layer.objects):
+        if ob is None:
+            continue
+        ob.select_set(False)
+
+
+def add_box(bm, loc, scale, mat_idx, euler=(0.0, 0.0, 0.0)):
+    geo = bmesh.ops.create_cube(bm, size=1.0)
+    verts = geo["verts"]
+    rot = Euler(euler).to_matrix()
+    origin = Vector(loc)
+    for v in verts:
+        p = Vector((v.co.x * scale[0], v.co.y * scale[1], v.co.z * scale[2]))
+        v.co = rot @ p + origin
+    faces = {f for v in verts for f in v.link_faces}
+    for f in faces:
+        f.material_index = mat_idx
+    return verts
+
+
+def pack_uvs(bm, margin=0.08):
+    uv = bm.loops.layers.uv.new("UVMap")
+    faces = list(bm.faces)
+    n = len(faces)
+    cols = max(1, math.ceil(math.sqrt(n)))
+    rows = max(1, math.ceil(n / cols))
+    cell_w = 1.0 / cols
+    cell_h = 1.0 / rows
+    pad_u = margin * cell_w * 0.5
+    pad_v = margin * cell_h * 0.5
+    usable_w = cell_w - 2.0 * pad_u
+    usable_h = cell_h - 2.0 * pad_v
+    for i, face in enumerate(faces):
+        col = i % cols
+        row = i // cols
+        nrm = face.normal
+        ax = abs(nrm.x)
+        ay = abs(nrm.y)
+        az = abs(nrm.z)
+        coords = []
+        for loop in face.loops:
+            co = loop.vert.co
+            if az >= ax and az >= ay:
+                coords.append((co.x, co.y))
+            elif ax >= ay:
+                coords.append((co.y, co.z))
+            else:
+                coords.append((co.x, co.z))
+        xs = [c[0] for c in coords]
+        ys = [c[1] for c in coords]
+        minx, maxx = min(xs), max(xs)
+        miny, maxy = min(ys), max(ys)
+        dx = max(maxx - minx, 1e-8)
+        dy = max(maxy - miny, 1e-8)
+        origin_u = col * cell_w + pad_u
+        origin_v = row * cell_h + pad_v
+        for loop, (x, y) in zip(face.loops, coords):
+            loop[uv].uv = (
+                origin_u + (x - minx) / dx * usable_w,
+                origin_v + (y - miny) / dy * usable_h,
+            )
+
+
+def hill_z_socket(tree, freq, amp):
+    pos = tree.nodes.new("GeometryNodeInputPosition")
+    sep = tree.nodes.new("ShaderNodeSeparateXYZ")
+    tree.links.new(pos.outputs["Position"], sep.inputs[0])
+    mx = tree.nodes.new("ShaderNodeMath")
+    mx.operation = "MULTIPLY"
+    mx.inputs[1].default_value = freq
+    my = tree.nodes.new("ShaderNodeMath")
+    my.operation = "MULTIPLY"
+    my.inputs[1].default_value = freq
+    tree.links.new(sep.outputs["X"], mx.inputs[0])
+    tree.links.new(sep.outputs["Y"], my.inputs[0])
+    sine = tree.nodes.new("ShaderNodeMath")
+    sine.operation = "SINE"
+    cose = tree.nodes.new("ShaderNodeMath")
+    cose.operation = "COSINE"
+    tree.links.new(mx.outputs[0], sine.inputs[0])
+    tree.links.new(my.outputs[0], cose.inputs[0])
+    prod = tree.nodes.new("ShaderNodeMath")
+    prod.operation = "MULTIPLY"
+    tree.links.new(sine.outputs[0], prod.inputs[0])
+    tree.links.new(cose.outputs[0], prod.inputs[1])
+    add1 = tree.nodes.new("ShaderNodeMath")
+    add1.operation = "ADD"
+    add1.inputs[1].default_value = 1.0
+    tree.links.new(prod.outputs[0], add1.inputs[0])
+    sc = tree.nodes.new("ShaderNodeMath")
+    sc.operation = "MULTIPLY"
+    sc.inputs[1].default_value = amp
+    tree.links.new(add1.outputs[0], sc.inputs[0])
+    return sc.outputs[0]
+
+
+def build_scatter_tree(verts, dirt, stone):
+    tree = bpy.data.node_groups.new("TerrainScatter", "GeometryNodeTree")
+    tree.interface.new_socket(
+        name="Geometry", in_out="OUTPUT", socket_type="NodeSocketGeometry",
+    )
+    go = tree.nodes.new("NodeGroupOutput")
+
+    hill = hill_z_socket(tree, FREQ, AMP)
+    off = tree.nodes.new("ShaderNodeCombineXYZ")
+    tree.links.new(hill, off.inputs["Z"])
+
+    grid = tree.nodes.new("GeometryNodeMeshGrid")
+    grid.inputs["Size X"].default_value = PATCH
+    grid.inputs["Size Y"].default_value = PATCH
+    grid.inputs["Vertices X"].default_value = verts
+    grid.inputs["Vertices Y"].default_value = verts
+    set_pos = tree.nodes.new("GeometryNodeSetPosition")
+    tree.links.new(grid.outputs["Mesh"], set_pos.inputs["Geometry"])
+    tree.links.new(off.outputs["Vector"], set_pos.inputs["Offset"])
+    lift = tree.nodes.new("GeometryNodeTransform")
+    lift.inputs["Translation"].default_value = (0.0, 0.0, SLAB_LIFT)
+    tree.links.new(set_pos.outputs["Geometry"], lift.inputs["Geometry"])
+    shade_t = tree.nodes.new("GeometryNodeSetShadeSmooth")
+    shade_t.inputs["Shade Smooth"].default_value = False
+    tree.links.new(lift.outputs["Geometry"], shade_t.inputs["Geometry"])
+    sm_d = tree.nodes.new("GeometryNodeSetMaterial")
+    sm_d.inputs["Material"].default_value = dirt
+    tree.links.new(shade_t.outputs["Geometry"], sm_d.inputs["Geometry"])
+
+    pts = tree.nodes.new("GeometryNodeMeshGrid")
+    pts.inputs["Size X"].default_value = ROCK_SPAN
+    pts.inputs["Size Y"].default_value = ROCK_SPAN
+    pts.inputs["Vertices X"].default_value = ROCK_GRID
+    pts.inputs["Vertices Y"].default_value = ROCK_GRID
+    idx = tree.nodes.new("GeometryNodeInputIndex")
+    jx = tree.nodes.new("ShaderNodeMath")
+    jx.operation = "MULTIPLY"
+    jx.inputs[1].default_value = 1.73
+    tree.links.new(idx.outputs["Index"], jx.inputs[0])
+    jxs = tree.nodes.new("ShaderNodeMath")
+    jxs.operation = "SINE"
+    tree.links.new(jx.outputs[0], jxs.inputs[0])
+    jxm = tree.nodes.new("ShaderNodeMath")
+    jxm.operation = "MULTIPLY"
+    jxm.inputs[1].default_value = 0.09
+    tree.links.new(jxs.outputs[0], jxm.inputs[0])
+    jy = tree.nodes.new("ShaderNodeMath")
+    jy.operation = "MULTIPLY"
+    jy.inputs[1].default_value = 2.19
+    tree.links.new(idx.outputs["Index"], jy.inputs[0])
+    jyc = tree.nodes.new("ShaderNodeMath")
+    jyc.operation = "COSINE"
+    tree.links.new(jy.outputs[0], jyc.inputs[0])
+    jym = tree.nodes.new("ShaderNodeMath")
+    jym.operation = "MULTIPLY"
+    jym.inputs[1].default_value = 0.09
+    tree.links.new(jyc.outputs[0], jym.inputs[0])
+    extra = tree.nodes.new("ShaderNodeMath")
+    extra.operation = "ADD"
+    extra.inputs[1].default_value = SLAB_LIFT
+    tree.links.new(hill, extra.inputs[0])
+    jitter = tree.nodes.new("ShaderNodeCombineXYZ")
+    tree.links.new(jxm.outputs[0], jitter.inputs["X"])
+    tree.links.new(jym.outputs[0], jitter.inputs["Y"])
+    tree.links.new(extra.outputs[0], jitter.inputs["Z"])
+    set_pts = tree.nodes.new("GeometryNodeSetPosition")
+    tree.links.new(pts.outputs["Mesh"], set_pts.inputs["Geometry"])
+    tree.links.new(jitter.outputs["Vector"], set_pts.inputs["Offset"])
+
+    cube = tree.nodes.new("GeometryNodeMeshCube")
+    cube.inputs["Size"].default_value = ROCK_SIZE
+    iop = tree.nodes.new("GeometryNodeInstanceOnPoints")
+    tree.links.new(set_pts.outputs["Geometry"], iop.inputs["Points"])
+    tree.links.new(cube.outputs["Mesh"], iop.inputs["Instance"])
+
+    ang = tree.nodes.new("ShaderNodeMath")
+    ang.operation = "MULTIPLY"
+    ang.inputs[1].default_value = 0.67
+    tree.links.new(idx.outputs["Index"], ang.inputs[0])
+    rot = tree.nodes.new("ShaderNodeCombineXYZ")
+    tree.links.new(ang.outputs[0], rot.inputs["Z"])
+    tree.links.new(rot.outputs["Vector"], iop.inputs["Rotation"])
+
+    mod = tree.nodes.new("ShaderNodeMath")
+    mod.operation = "MODULO"
+    mod.inputs[1].default_value = 3.0
+    tree.links.new(idx.outputs["Index"], mod.inputs[0])
+    div = tree.nodes.new("ShaderNodeMath")
+    div.operation = "DIVIDE"
+    div.inputs[1].default_value = 3.0
+    tree.links.new(mod.outputs[0], div.inputs[0])
+    mul_s = tree.nodes.new("ShaderNodeMath")
+    mul_s.operation = "MULTIPLY"
+    mul_s.inputs[1].default_value = 0.22
+    tree.links.new(div.outputs[0], mul_s.inputs[0])
+    add_s = tree.nodes.new("ShaderNodeMath")
+    add_s.operation = "ADD"
+    add_s.inputs[1].default_value = 0.84
+    tree.links.new(mul_s.outputs[0], add_s.inputs[0])
+    scl = tree.nodes.new("ShaderNodeCombineXYZ")
+    tree.links.new(add_s.outputs[0], scl.inputs["X"])
+    tree.links.new(add_s.outputs[0], scl.inputs["Y"])
+    tree.links.new(add_s.outputs[0], scl.inputs["Z"])
+    tree.links.new(scl.outputs["Vector"], iop.inputs["Scale"])
+
+    realize = tree.nodes.new("GeometryNodeRealizeInstances")
+    tree.links.new(iop.outputs["Instances"], realize.inputs["Geometry"])
+    sm_s = tree.nodes.new("GeometryNodeSetMaterial")
+    sm_s.inputs["Material"].default_value = stone
+    tree.links.new(realize.outputs["Geometry"], sm_s.inputs["Geometry"])
+
+    join = tree.nodes.new("GeometryNodeJoinGeometry")
+    tree.links.new(sm_d.outputs["Geometry"], join.inputs[0])
+    tree.links.new(sm_s.outputs["Geometry"], join.inputs[0])
+    shade = tree.nodes.new("GeometryNodeSetShadeSmooth")
+    shade.inputs["Shade Smooth"].default_value = False
+    tree.links.new(join.outputs["Geometry"], shade.inputs["Geometry"])
+    tree.links.new(shade.outputs["Geometry"], go.inputs["Geometry"])
+    return tree
+
+
+def eval_to_mesh(obj, name):
+    bpy.context.view_layer.update()
+    dg = bpy.context.evaluated_depsgraph_get()
+    ev = obj.evaluated_get(dg)
+    em = ev.to_mesh()
+    try:
+        me = bpy.data.meshes.new(name)
+        me.from_pydata(
+            [tuple(v.co) for v in em.vertices],
+            [],
+            [tuple(p.vertices) for p in em.polygons],
+        )
+        src_idx = [p.material_index for p in em.polygons]
+        me.update()
+        for poly, idx in zip(me.polygons, src_idx):
+            poly.material_index = idx
+    finally:
+        ev.to_mesh_clear()
+    return me
+
+
+def slabify(bm, floor_z=0.0):
+    bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces))
+    boundary = [e for e in bm.edges if e.is_boundary]
+    if not boundary:
+        return
+    ret = bmesh.ops.extrude_edge_only(bm, edges=boundary)
+    verts = [g for g in ret["geom"] if isinstance(g, bmesh.types.BMVert)]
+    for v in verts:
+        v.co.z = floor_z
+    bottom = [
+        e for e in bm.edges
+        if e.is_boundary
+        and abs(e.verts[0].co.z - floor_z) < 1e-5
+        and abs(e.verts[1].co.z - floor_z) < 1e-5
+    ]
+    if bottom:
+        try:
+            bmesh.ops.edgeloop_fill(bm, edges=bottom)
+        except Exception:
+            bmesh.ops.contextual_create(bm, geom=bottom)
+    for f in bm.faces:
+        if f.material_index not in (DIRT_IDX, STONE_IDX):
+            f.material_index = DIRT_IDX
+
+
+def masonry_from_cubes(bm, lump, bevel_offset, bevel_segments):
+    stone_faces = [f for f in bm.faces if f.material_index == STONE_IDX]
+    visited = set()
+    islands = []
+    for face in stone_faces:
+        if face in visited:
+            continue
+        stack = [face]
+        island = []
+        while stack:
+            cur = stack.pop()
+            if cur in visited:
+                continue
+            visited.add(cur)
+            island.append(cur)
+            for edge in cur.edges:
+                for other in edge.link_faces:
+                    if other.material_index == STONE_IDX and other not in visited:
+                        stack.append(other)
+        islands.append(island)
+
+    specs = []
+    for island in islands:
+        verts = {v for f in island for v in f.verts}
+        xs = [v.co.x for v in verts]
+        ys = [v.co.y for v in verts]
+        zs = [v.co.z for v in verts]
+        cx = 0.5 * (min(xs) + max(xs))
+        cy = 0.5 * (min(ys) + max(ys))
+        cz = 0.5 * (min(zs) + max(zs))
+        z0 = min(zs)
+        sx = 0.17 + 0.04 * math.sin(cx * 8.1)
+        sy = 0.15 + 0.03 * math.cos(cy * 6.4)
+        sz = 0.20 + 0.05 * math.sin(cx * 4.2 + cy * 3.1)
+        ex = 0.38 * math.sin(cx * 5.1)
+        ey = 0.30 * math.cos(cy * 4.3)
+        ez = cx * 3.7 + cy * 2.1
+        cz = z0 + sz * 0.30
+        specs.append((cx, cy, cz, sx, sy, sz, ex, ey, ez))
+
+    if stone_faces:
+        bmesh.ops.delete(bm, geom=stone_faces, context="FACES")
+        loose = [v for v in bm.verts if not v.link_faces]
+        if loose:
+            bmesh.ops.delete(bm, geom=loose, context="VERTS")
+
+    for cx, cy, cz, sx, sy, sz, ex, ey, ez in specs:
+        verts = add_box(
+            bm,
+            (cx, cy, cz),
+            (sx, sy, sz),
+            STONE_IDX,
+            euler=(ex, ey, ez),
+        )
+        if bevel_offset > 0.0:
+            edges = list({e for v in verts for e in v.link_edges})
+            if edges:
+                ret = bmesh.ops.bevel(
+                    bm,
+                    geom=edges,
+                    offset=bevel_offset,
+                    segments=bevel_segments,
+                    profile=0.5,
+                    affect="EDGES",
+                    clamp_overlap=True,
+                )
+                for f in ret.get("faces") or []:
+                    f.material_index = STONE_IDX
+
+
+def build_terrain_mesh(name, grid_verts, lump, bevel_offset, bevel_segments, dirt, stone):
+    carrier = bpy.data.meshes.new(name + "Carrier")
+    carrier.vertices.add(1)
+    obj = bpy.data.objects.new(name + "GN", carrier)
+    bpy.context.collection.objects.link(obj)
+    tree = build_scatter_tree(grid_verts, dirt, stone)
+    mod = obj.modifiers.new("terrain_scatter", "NODES")
+    mod.node_group = tree
+    realized = eval_to_mesh(obj, name + "Eval")
+    bpy.data.objects.remove(obj, do_unlink=True)
+
+    bm = bmesh.new()
+    try:
+        bm.from_mesh(realized)
+        bm.verts.ensure_lookup_table()
+        bm.edges.ensure_lookup_table()
+        bm.faces.ensure_lookup_table()
+        slabify(bm, floor_z=0.0)
+        bm.verts.ensure_lookup_table()
+        bm.faces.ensure_lookup_table()
+        masonry_from_cubes(bm, lump, bevel_offset, bevel_segments)
+        xs = [v.co.x for v in bm.verts]
+        ys = [v.co.y for v in bm.verts]
+        zs = [v.co.z for v in bm.verts]
+        cx = 0.5 * (min(xs) + max(xs))
+        cy = 0.5 * (min(ys) + max(ys))
+        zmin = min(zs)
+        for v in bm.verts:
+            v.co.x -= cx
+            v.co.y -= cy
+            v.co.z -= zmin
+            if v.co.z < 0.0:
+                v.co.z = 0.0
+        pack_uvs(bm)
+        bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces))
+        for face in bm.faces:
+            face.smooth = False
+        me = bpy.data.meshes.new(name)
+        bm.to_mesh(me)
+        me.update()
+        for poly in me.polygons:
+            poly.use_smooth = False
+    finally:
+        bm.free()
+    out = bpy.data.objects.new(name, me)
+    bpy.context.collection.objects.link(out)
+    return out
+
+
+def principled(name, color, metallic, roughness):
+    mat = bpy.data.materials.new(name)
+    mat.use_nodes = True
+    bsdf = mat.node_tree.nodes["Principled BSDF"]
+    bsdf.inputs["Base Color"].default_value = color
+    bsdf.inputs["Metallic"].default_value = metallic
+    bsdf.inputs["Roughness"].default_value = roughness
+    return mat
+
+
+def assign_slots(obj, dirt, stone):
+    # Do not materials.clear() — that resets polygon material_index to 0
+    # on this Blender, which would drop stone faces onto dirt.
+    mats = obj.data.materials
+    wanted = (dirt, stone)
+    for i, mat in enumerate(wanted):
+        if i < len(mats):
+            mats[i] = mat
+        else:
+            mats.append(mat)
+
+
+def world_bbox(obj):
+    corners = [obj.matrix_world @ Vector(c) for c in obj.bound_box]
+    xs = [c.x for c in corners]
+    ys = [c.y for c in corners]
+    zs = [c.z for c in corners]
+    return (min(xs), min(ys), min(zs), max(xs), max(ys), max(zs))
+
+
+def uv_stats(mesh):
+    uv = mesh.uv_layers.active
+    if uv is None:
+        return 0.0, 0.0, 1.0, 1.0, 0, 1.0
+    data = uv.data
+    us = [loop.uv[0] for loop in data]
+    vs = [loop.uv[1] for loop in data]
+    aabbs = []
+    for poly in mesh.polygons:
+        pu = [data[i].uv[0] for i in poly.loop_indices]
+        pv = [data[i].uv[1] for i in poly.loop_indices]
+        aabbs.append((min(pu), min(pv), max(pu), max(pv)))
+    overlap = 0.0
+    for i in range(len(aabbs)):
+        a = aabbs[i]
+        for j in range(i + 1, len(aabbs)):
+            b = aabbs[j]
+            x0 = max(a[0], b[0])
+            y0 = max(a[1], b[1])
+            x1 = min(a[2], b[2])
+            y1 = min(a[3], b[3])
+            overlap += max(0.0, x1 - x0) * max(0.0, y1 - y0)
+    return min(us), min(vs), max(us), max(vs), overlap, len(aabbs)
+
+
+def make_lod(obj, name, ratio, skip_decimate):
+    mesh = obj.data.copy()
+    lod = bpy.data.objects.new(name, mesh)
+    lod.matrix_world = obj.matrix_world.copy()
+    bpy.context.scene.collection.objects.link(lod)
+    if not skip_decimate and 0.0 < ratio < 1.0:
+        mod = lod.modifiers.new("DecimateBudget", "DECIMATE")
+        mod.decimate_type = "COLLAPSE"
+        mod.ratio = ratio
+    return lod
+
+
+def convex_hull_collider(obj, name):
+    mesh = bpy.data.meshes.new(name)
+    bm = bmesh.new()
+    try:
+        bm.from_mesh(obj.data)
+        result = bmesh.ops.convex_hull(bm, input=list(bm.verts))
+        interior = result.get("geom_interior") or []
+        unused = result.get("geom_unused") or []
+        if interior:
+            bmesh.ops.delete(bm, geom=interior, context="VERTS")
+        if unused:
+            bmesh.ops.delete(bm, geom=unused, context="VERTS")
+        bm.to_mesh(mesh)
+        mesh.update()
+    finally:
+        bm.free()
+    collider = bpy.data.objects.new(name, mesh)
+    bpy.context.collection.objects.link(collider)
+    collider.matrix_world = obj.matrix_world.copy()
+    return collider
+
+
+def setup_bake_image(obj, target_mat, size=BAKE_RES):
+    if not obj.data.uv_layers:
+        return None, None
+    img = bpy.data.images.new("TerrainNrm", size, size, alpha=True, float_buffer=False)
+    img.colorspace_settings.name = "Non-Color"
+    nodes = target_mat.node_tree.nodes
+    tex = nodes.new("ShaderNodeTexImage")
+    tex.image = img
+    nodes.active = tex
+    tex.select = True
+    obj.active_material_index = DIRT_IDX
+    return img, tex
+
+
+def bake_normal(high, low):
+    scene = bpy.context.scene
+    scene.render.engine = "CYCLES"
+    scene.cycles.device = "CPU"
+    scene.cycles.samples = 1
+    scene.cycles.use_denoising = False
+    deselect_all()
+    high.select_set(True)
+    low.select_set(True)
+    bpy.context.view_layer.objects.active = low
+    return bpy.ops.object.bake(
+        type="NORMAL",
+        use_selected_to_active=True,
+        cage_extrusion=CAGE_EXTRUSION,
+        use_cage=False,
+        normal_space="TANGENT",
+        margin=4,
+        margin_type="ADJACENT_FACES",
+        use_clear=True,
+        target="IMAGE_TEXTURES",
+    )
+
+
+def export_unity(path, objects):
+    deselect_all()
+    for ob in objects:
+        ob.select_set(True)
+    bpy.context.view_layer.objects.active = objects[0]
+    bpy.ops.export_scene.gltf(
+        filepath=path,
+        use_selection=True,
+        export_yup=True,
+        export_apply=True,
+        export_draco_mesh_compression_enable=False,
+        export_animations=False,
+    )
+
+
+def check(skip_decimate):
+    bpy.ops.wm.read_factory_settings(use_empty=True)
+    dirt = principled("TerrainDirt", (0.30, 0.17, 0.07, 1.0), 0.0, 0.90)
+    stone = principled("TerrainStone", (0.56, 0.53, 0.48, 1.0), 0.0, 0.76)
+    low = build_terrain_mesh("TerrainLow", 9, 0.10, 0.022, 2, dirt, stone)
+    high = build_terrain_mesh("TerrainHigh", 13, 0.10, 0.022, 4, dirt, stone)
+    assign_slots(low, dirt, stone)
+    assign_slots(high, dirt, stone)
+
+    if low.data is None or len(low.data.polygons) < 6:
+        return fail("terrain mesh did not build", 3), None, None, None, None, None
+
+    base_tris = triangle_count(low.data)
+    mats = [s for s in low.data.materials if s is not None]
+    nmat = len(mats)
+    distinct_mats = len({id(s) for s in mats})
+    idx_counts = {}
+    for poly in low.data.polygons:
+        idx_counts[poly.material_index] = idx_counts.get(poly.material_index, 0) + 1
+    print(f"measured mat_index_counts={idx_counts}")
+    u0, v0, u1, v1, overlap, nfaces = uv_stats(low.data)
+    bb = world_bbox(low)
+    size_x = bb[3] - bb[0]
+    size_y = bb[4] - bb[1]
+    size_z = bb[5] - bb[2]
+
+    img, tex = setup_bake_image(low, dirt)
+    if img is None:
+        return fail("terrain has no UV layer", 3), None, None, None, None, None
+    bake_result = bake_normal(high, low)
+
+    lod1 = make_lod(low, "TerrainLOD1", LOD1_TARGET, skip_decimate)
+    lod2 = make_lod(low, "TerrainLOD2", LOD2_TARGET, skip_decimate)
+    bpy.context.view_layer.update()
+    lod1_tris = evaluated_triangle_count(lod1)
+    lod2_tris = evaluated_triangle_count(lod2)
+    r1 = lod1_tris / base_tris if base_tris else 0.0
+    r2 = lod2_tris / base_tris if base_tris else 0.0
+
+    collider_src = build_terrain_mesh(
+        "TerrainColSrc", 9, 0.0, 0.0, 1, dirt, stone
+    )
+    collider = convex_hull_collider(collider_src, "TerrainCollider")
+    bpy.data.objects.remove(collider_src, do_unlink=True)
+    col_tris = triangle_count(collider.data)
+
+    export_path = os.path.join(
+        tempfile.gettempdir(),
+        f"bdt_terrain_scatter_{os.getpid()}.glb",
+    )
+    if os.path.exists(export_path):
+        os.remove(export_path)
+    export_unity(export_path, [low, collider])
+    export_size = os.path.getsize(export_path) if os.path.isfile(export_path) else 0
+
+    print(f"blender={tuple(bpy.app.version)} skip_decimate={skip_decimate}")
+    print(
+        f"measured base_tris={base_tris} lod1_tris={lod1_tris} "
+        f"lod2_tris={lod2_tris} r1={r1:.4f} r2={r2:.4f}"
+    )
+    print(
+        f"measured nmat={nmat} uv=({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f}) "
+        f"overlap={overlap:.6f} nfaces={nfaces}"
+    )
+    print(
+        f"measured bbox=({size_x:.4f},{size_y:.4f},{size_z:.4f}) "
+        f"outer={OUTER_SIZE} zmin={bb[2]:.4f}"
+    )
+    print(
+        f"measured collider_tris={col_tris} bake={bake_result} "
+        f"bake_has_data={img.has_data} export_bytes={export_size}"
+    )
+
+    if not (BASE_TRIS_MIN <= base_tris <= BASE_TRIS_MAX):
+        return fail(
+            f"base tris {base_tris} not in [{BASE_TRIS_MIN}, {BASE_TRIS_MAX}]",
+            4,
+        ), None, None, None, None, None
+    if nmat != MATERIAL_COUNT or distinct_mats != MATERIAL_COUNT:
+        return fail(
+            f"material slots {nmat} distinct {distinct_mats} != {MATERIAL_COUNT}",
+            5,
+        ), None, None, None, None, None
+    if idx_counts.get(STONE_IDX, 0) < STONE_FACES_MIN:
+        return fail(
+            f"stone faces {idx_counts.get(STONE_IDX, 0)} < {STONE_FACES_MIN}",
+            5,
+        ), None, None, None, None, None
+    if u0 < -UV_EPS or v0 < -UV_EPS or u1 > 1.0 + UV_EPS or v1 > 1.0 + UV_EPS:
+        return fail(
+            f"UVs outside 0..1: ({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f})",
+            6,
+        ), None, None, None, None, None
+    if overlap > UV_OVERLAP_MAX:
+        return fail(
+            f"UV AABB overlap {overlap:.6f} > {UV_OVERLAP_MAX}",
+            7,
+        ), None, None, None, None, None
+    if (
+        abs(size_x - OUTER_SIZE[0]) > BBOX_TOL
+        or abs(size_y - OUTER_SIZE[1]) > BBOX_TOL
+        or abs(size_z - OUTER_SIZE[2]) > BBOX_TOL
+    ):
+        return fail(
+            f"bbox ({size_x:.4f},{size_y:.4f},{size_z:.4f}) "
+            f"off outer {OUTER_SIZE}",
+            8,
+        ), None, None, None, None, None
+    if not (LOD1_RATIO_MIN <= r1 <= LOD1_RATIO_MAX):
+        return fail(
+            f"LOD1 ratio {r1:.4f} not in [{LOD1_RATIO_MIN}, {LOD1_RATIO_MAX}] "
+            "(--skip-decimate is the designed fail)",
+            9,
+        ), None, None, None, None, None
+    if not (LOD2_RATIO_MIN <= r2 <= LOD2_RATIO_MAX):
+        return fail(
+            f"LOD2 ratio {r2:.4f} not in [{LOD2_RATIO_MIN}, {LOD2_RATIO_MAX}]",
+            9,
+        ), None, None, None, None, None
+    if col_tris > COLLIDER_TRIS_MAX:
+        return fail(
+            f"collider tris {col_tris} > {COLLIDER_TRIS_MAX}",
+            11,
+        ), None, None, None, None, None
+    if bake_result != {"FINISHED"} or not img.has_data:
+        return fail(
+            f"bake failed result={bake_result} has_data={img.has_data}",
+            12,
+        ), None, None, None, None, None
+    if export_size <= 0:
+        return fail("export file missing or empty", 13), None, None, None, None, None
+    return 0, low, high, dirt, tex, collider
+
+
+def wire_normal(mat, tex):
+    nt = mat.node_tree
+    bsdf = nt.nodes["Principled BSDF"]
+    nrm = nt.nodes.new("ShaderNodeNormalMap")
+    nrm.inputs["Strength"].default_value = 1.0
+    nt.links.new(tex.outputs["Color"], nrm.inputs["Color"])
+    nt.links.new(nrm.outputs["Normal"], bsdf.inputs["Normal"])
+
+
+def render_still(low, dirt, tex, path, engine):
+    scene = bpy.context.scene
+    wire_normal(dirt, tex)
+    for ob in list(scene.objects):
+        if ob.type == "MESH" and ob != low:
+            ob.hide_render = True
+            ob.hide_viewport = True
+
+    low.rotation_euler.z = math.radians(-28.0)
+    low.rotation_euler.x = math.radians(0.0)
+
+    floor_me = bpy.data.meshes.new("Floor")
+    bm = bmesh.new()
+    try:
+        bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0)
+        bm.to_mesh(floor_me)
+    finally:
+        bm.free()
+    fmat = bpy.data.materials.new("Floor")
+    fmat.use_nodes = True
+    fb = fmat.node_tree.nodes["Principled BSDF"]
+    fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0)
+    fb.inputs["Roughness"].default_value = 0.7
+    floor_me.materials.append(fmat)
+    floor = bpy.data.objects.new("Floor", floor_me)
+    scene.collection.objects.link(floor)
+    wall = bpy.data.objects.new("Wall", floor_me.copy())
+    wall.location = (0.0, 8.5, 0.0)
+    wall.rotation_euler = (math.radians(90), 0.0, 0.0)
+    scene.collection.objects.link(wall)
+
+    world = bpy.data.worlds.new("World")
+    world.use_nodes = True
+    world.node_tree.nodes["Background"].inputs["Color"].default_value = (
+        0.02, 0.021, 0.025, 1.0,
+    )
+    scene.world = world
+
+    def light(name, loc, energy, size, col, rot):
+        ld = bpy.data.lights.new(name, "AREA")
+        ld.energy = energy
+        ld.size = size
+        ld.color = col
+        ob = bpy.data.objects.new(name, ld)
+        ob.location = loc
+        ob.rotation_euler = tuple(math.radians(a) for a in rot)
+        scene.collection.objects.link(ob)
+
+    light("Key", (-3.6, -5.0, 5.8), 680.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36))
+    light("Fill", (5.0, -3.6, 2.6), 48.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50))
+    light("Wedge", (2.4, 4.2, 4.1), 640.0, 5.5, (1.0, 0.70, 0.40), (-70, 0, 198))
+
+    cam_data = bpy.data.cameras.new("Cam")
+    cam_data.lens = 50.0
+    cam = bpy.data.objects.new("Cam", cam_data)
+    cam.location = (2.57, -3.51, 2.24)
+    scene.collection.objects.link(cam)
+    aim = bpy.data.objects.new("Aim", None)
+    aim.location = (0.0, 0.0, 0.24)
+    scene.collection.objects.link(aim)
+    con = cam.constraints.new("TRACK_TO")
+    con.target = aim
+    con.track_axis = "TRACK_NEGATIVE_Z"
+    con.up_axis = "UP_Y"
+    scene.camera = cam
+
+    scene.render.engine = "CYCLES" if engine == "cycles" else eevee_engine_id()
+    if engine == "cycles":
+        scene.cycles.samples = 32
+        scene.cycles.device = "CPU"
+    else:
+        try:
+            scene.eevee.taa_render_samples = 64
+        except AttributeError:
+            pass
+    scene.render.resolution_x = 1280
+    scene.render.resolution_y = 720
+    scene.render.image_settings.file_format = (
+        "WEBP" if path.lower().endswith(".webp") else "PNG"
+    )
+    if path.lower().endswith(".webp"):
+        scene.render.image_settings.quality = 90
+    scene.render.filepath = path
+    scene.view_settings.view_transform = "Standard"
+
+    fcode = gallery_framing.check_framing(
+        scene, cam, hero=[low], elements=[low], stage=[floor, wall],
+    )
+    if fcode:
+        return fcode
+    bpy.ops.render.render(write_still=True)
+    if not (os.path.exists(path) and os.path.getsize(path) > 0):
+        return fail("render produced no file", 14)
+    return 0
+
+
+def main():
+    argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []
+    p = argparse.ArgumentParser()
+    p.add_argument("--output", default=None)
+    p.add_argument("--engine", default="eevee", choices=("eevee", "cycles"))
+    p.add_argument(
+        "--skip-decimate",
+        action="store_true",
+        help="falsification: skip the LOD DECIMATE stage",
+    )
+    args = p.parse_args(argv)
+
+    code, low, _high, dirt, tex, _col = check(args.skip_decimate)
+    if code:
+        return code
+    if args.output:
+        rcode = render_still(low, dirt, tex, os.path.abspath(args.output), args.engine)
+        if rcode:
+            return rcode
+        print(f"rendered still {args.output}")
+    print("terrain-scatter OK")
+    return 0
+
+
+if __name__ == "__main__":
+    try:
+        sys.exit(main())
+    except Exception as e:
+        traceback.print_exc()
+        print(f"FATAL: {e}", file=sys.stderr)
+        sys.exit(1)
+
+
+
+ +
+
+ generated from examples/gallery.json + CC-BY-NC-ND-4.0 + exit 0 +
+
+ + + diff --git a/showcase/fence-kit/README.md b/showcase/fence-kit/README.md new file mode 100644 index 0000000..4c3c6a1 --- /dev/null +++ b/showcase/fence-kit/README.md @@ -0,0 +1,75 @@ +# Fence kit + +A showcase piece, not an example. Procedural post-and-rail fence +section (two posts, pyramidal caps, three rails, kickboard, brace, +iron shoes and straps) then the shipped pipeline: unique-cell UVs, +Cycles high-to-low normal bake, LOD chain, convex collider, Unity +glTF export. + +It asserts **budget conformance** of the generated result. It does not +witness an API contract. "It rendered without error" is not a check. +AABB X is the tile width so adjacent copies meet; this piece does not +re-witness the `modular-kit-snap` snap contract. + +**Composes** skills `mesh-editing-and-bmesh`, `bake-high-to-low`, +`depsgraph-and-evaluated-data`, `engine-export-presets`, and snippets +`bake_normal_high_to_low.py`, `setup_bake_target_image.py`, +`lod_chain.py` / `decimate_to_budget.py`, `convex_hull_collider.py`, +`export_preset_unity.py` (helpers copied, not imported as a package). + +## Budgets + +Declared as named constants; every gate **recomputes** from the mesh, +materials, UVs, evaluated LOD, collider, or export file. + +| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) | +| --- | --- | --- | +| Base triangles | 1160–1280 | 1212 / 1212 / 1212 | +| LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | +| LOD2 ratio | 0.10–0.35 of base | 0.2195 / 0.2195 / 0.2079 | +| Materials | exactly 2 distinct, ≥24 metal faces | 2 slots, 120 metal | +| UVs | in `0..1`, AABB overlap ≤ 1e-5 | in range, overlap 0 | +| Outer AABB | (1.642, 0.157, 1.235) m ± 0.01 | (1.6418, 0.1574, 1.2350), zmin 0 | +| Collider tris | ≤ 96 | 62 | +| Export | written, size > 0 | 93232 / 93232 / 93224 bytes | + +DECIMATE COLLAPSE triangle counts are **not** identical across series — +5.2.1 is more aggressive on LOD2. The gate is a ratio band, not an +exact count. Bake pixels are stochastic; the gate is `has_data` plus +operator `FINISHED`, not byte-identity. Construction uses no RNG. + +`--skip-decimate` skips the LOD DECIMATE stage so LOD1 ratio is 1.0 and +exit 9 fires. That is the named budget the falsifier violates. + +## Run + +```bash +blender --background --python fence_kit.py -- +blender --background --python fence_kit.py -- --skip-decimate +blender --background --python fence_kit.py -- --output fence.png +``` + +Smoke does not pass `--output` or `--skip-decimate`. + +## Exit codes + +File-local. `9` is a valid check code. `10` is reserved for +`gallery_framing.check_framing` on the `--output` path. + +| Code | Meaning | +| --- | --- | +| 0 | Success | +| 1 | Uncaught exception (FATAL wrapper) | +| 2 | argparse / usage | +| 3 | Mesh did not build / no UV layer | +| 4 | Base triangle count outside range | +| 5 | Material count ≠ 2 distinct slots, or metal faces missing | +| 6 | UVs outside 0..1 | +| 7 | UV AABB overlap above tolerance | +| 8 | World AABB off declared outer size | +| 9 | LOD ratio band (`--skip-decimate` lands here) | +| 10 | Framing gate (render path only) | +| 11 | Collider triangle count above ceiling | +| 12 | Bake did not finish or image has no data | +| 13 | Export file missing or empty | +| 14 | `--output` produced no file | diff --git a/showcase/fence-kit/fence_kit.py b/showcase/fence-kit/fence_kit.py new file mode 100644 index 0000000..5ca5b7b --- /dev/null +++ b/showcase/fence-kit/fence_kit.py @@ -0,0 +1,712 @@ +"""Game-ready post-and-rail fence kit — a showcase piece, not an example. + +Asserts budget conformance of a tiling timber fence section after +composing shipped pipeline pieces: bmesh construction, UVs, two +materials, high-to-low normal bake, LOD chain, convex collider, +Unity glTF export. + +Budgets are declared below and recomputed from the generated result. +They are not API-contract witnesses. ``--skip-decimate`` skips the LOD +DECIMATE stage so the LOD-ratio budget fails. + +No RNG. Construction is closed-form. AABB X is the tile width so +adjacent copies meet; this piece does not re-witness the modular-kit +snap contract. DECIMATE COLLAPSE triangle counts are not byte-identical +across Blender versions — the LOD gate is a ratio band, not an exact +count. + + blender --background --python fence_kit.py -- + blender --background --python fence_kit.py -- --skip-decimate + blender --background --python fence_kit.py -- --output fence.png +""" +import argparse +import math +import os +import sys +import tempfile +import traceback + +import bmesh +import bpy +from mathutils import Euler, Vector + +_REPO = os.path.abspath( + os.path.join(os.path.dirname(os.path.abspath(__file__)), os.pardir, os.pardir) +) +sys.path.insert(0, os.path.join(_REPO, "examples")) +sys.dont_write_bytecode = True +import gallery_framing # noqa: E402 + +TILE = 1.60 +POST_W = 0.110 +POST_H = 1.14 +CAP_H = 0.095 +RAIL_Y = 0.055 +RAIL_Z = 0.064 +RAIL_ZS = (0.30, 0.58, 0.86) +KICK_Z = 0.125 +KICK_Y = 0.040 +BRACE_T = 0.042 +IRON_T = 0.016 +SHOE_H = 0.034 +SHOE_SCALE = 1.38 + +BBOX_TOL = 0.01 +OUTER_SIZE = (1.642, 0.157, 1.235) +BASE_TRIS_MIN = 1160 +BASE_TRIS_MAX = 1280 +LOD1_RATIO_MIN = 0.32 +LOD1_RATIO_MAX = 0.62 +LOD2_RATIO_MIN = 0.10 +LOD2_RATIO_MAX = 0.35 +LOD1_TARGET = 0.50 +LOD2_TARGET = 0.22 +MATERIAL_COUNT = 2 +UV_EPS = 1e-4 +UV_OVERLAP_MAX = 1e-5 +COLLIDER_TRIS_MAX = 96 +BAKE_RES = 256 +CAGE_EXTRUSION = 0.06 +METAL_FACES_MIN = 24 + +WOOD_IDX = 0 +METAL_IDX = 1 + + +def eevee_engine_id(): + return "BLENDER_EEVEE" if bpy.app.version >= (5, 0, 0) else "BLENDER_EEVEE_NEXT" + + +def fail(msg, code): + print(f"ERROR: {msg}", file=sys.stderr) + return code + + +def triangle_count(mesh): + mesh.calc_loop_triangles() + return len(mesh.loop_triangles) + + +def evaluated_triangle_count(obj): + depsgraph = bpy.context.evaluated_depsgraph_get() + eval_obj = obj.evaluated_get(depsgraph) + eval_mesh = eval_obj.to_mesh() + try: + eval_mesh.calc_loop_triangles() + return len(eval_mesh.loop_triangles) + finally: + eval_obj.to_mesh_clear() + + +def deselect_all(): + for ob in list(bpy.context.view_layer.objects): + if ob is None: + continue + ob.select_set(False) + + +def add_box(bm, loc, scale, mat_idx, euler=(0.0, 0.0, 0.0)): + geo = bmesh.ops.create_cube(bm, size=1.0) + verts = geo["verts"] + rot = Euler(euler).to_matrix() + origin = Vector(loc) + for v in verts: + p = Vector((v.co.x * scale[0], v.co.y * scale[1], v.co.z * scale[2])) + v.co = rot @ p + origin + faces = {f for v in verts for f in v.link_faces} + for f in faces: + f.material_index = mat_idx + return verts + + +def add_cone(bm, loc, radius1, radius2, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)): + geo = bmesh.ops.create_cone( + bm, + cap_ends=True, + cap_tris=False, + segments=segments, + radius1=radius1, + radius2=radius2, + depth=depth, + ) + verts = geo["verts"] + rot = Euler(euler).to_matrix() + origin = Vector(loc) + for v in verts: + v.co = rot @ v.co + origin + faces = {f for v in verts for f in v.link_faces} + for f in faces: + f.material_index = mat_idx + return verts + + +def pack_uvs(bm, margin=0.08): + uv = bm.loops.layers.uv.new("UVMap") + faces = list(bm.faces) + n = len(faces) + cols = max(1, math.ceil(math.sqrt(n))) + rows = max(1, math.ceil(n / cols)) + cell_w = 1.0 / cols + cell_h = 1.0 / rows + pad_u = margin * cell_w * 0.5 + pad_v = margin * cell_h * 0.5 + usable_w = cell_w - 2.0 * pad_u + usable_h = cell_h - 2.0 * pad_v + for i, face in enumerate(faces): + col = i % cols + row = i // cols + nrm = face.normal + ax = abs(nrm.x) + ay = abs(nrm.y) + az = abs(nrm.z) + coords = [] + for loop in face.loops: + co = loop.vert.co + if az >= ax and az >= ay: + coords.append((co.x, co.y)) + elif ax >= ay: + coords.append((co.y, co.z)) + else: + coords.append((co.x, co.z)) + xs = [c[0] for c in coords] + ys = [c[1] for c in coords] + minx, maxx = min(xs), max(xs) + miny, maxy = min(ys), max(ys) + dx = max(maxx - minx, 1e-8) + dy = max(maxy - miny, 1e-8) + origin_u = col * cell_w + pad_u + origin_v = row * cell_h + pad_v + for loop, (x, y) in zip(face.loops, coords): + loop[uv].uv = ( + origin_u + (x - minx) / dx * usable_w, + origin_v + (y - miny) / dy * usable_h, + ) + + +def build_fence_mesh(name, bevel_offset, bevel_segments): + bm = bmesh.new() + try: + wood_verts = [] + post_xs = (-(TILE / 2.0 - POST_W / 2.0), TILE / 2.0 - POST_W / 2.0) + for px in post_xs: + wood_verts.extend( + add_box(bm, (px, 0.0, POST_H / 2.0), (POST_W, POST_W, POST_H), WOOD_IDX) + ) + wood_verts.extend( + add_cone( + bm, + (px, 0.0, POST_H + CAP_H / 2.0), + POST_W * 0.72, + 0.010, + CAP_H, + 4, + WOOD_IDX, + euler=(0.0, 0.0, math.pi / 4.0), + ) + ) + + rail_len = TILE - POST_W * 0.18 + for z in RAIL_ZS: + wood_verts.extend( + add_box(bm, (0.0, 0.0, z), (rail_len, RAIL_Y, RAIL_Z), WOOD_IDX) + ) + + wood_verts.extend( + add_box( + bm, + (0.0, 0.0, KICK_Z / 2.0), + (TILE - POST_W * 0.22, KICK_Y, KICK_Z), + WOOD_IDX, + ) + ) + + span = TILE - POST_W + rise = RAIL_ZS[-1] - RAIL_ZS[0] + brace_len = math.hypot(span, rise) + brace_ang = math.atan2(rise, span) + wood_verts.extend( + add_box( + bm, + (0.0, -POST_W * 0.55, (RAIL_ZS[0] + RAIL_ZS[-1]) / 2.0), + (brace_len, BRACE_T, BRACE_T), + WOOD_IDX, + euler=(0.0, -brace_ang, 0.0), + ) + ) + + if bevel_offset > 0.0: + edges = list({e for v in wood_verts for e in v.link_edges}) + bmesh.ops.bevel( + bm, + geom=edges, + offset=bevel_offset, + segments=bevel_segments, + profile=0.5, + affect="EDGES", + clamp_overlap=True, + ) + + for px in post_xs: + add_box( + bm, + (px, 0.0, SHOE_H / 2.0), + (POST_W * SHOE_SCALE, POST_W * SHOE_SCALE, SHOE_H), + METAL_IDX, + ) + sign = 1.0 if px > 0.0 else -1.0 + for z in RAIL_ZS: + add_box( + bm, + (px, POST_W / 2.0 + IRON_T / 2.0, z), + (POST_W * 0.88, IRON_T, RAIL_Z * 1.40), + METAL_IDX, + ) + add_box( + bm, + (px, -(POST_W / 2.0 + IRON_T / 2.0), z), + (POST_W * 0.88, IRON_T, RAIL_Z * 1.40), + METAL_IDX, + ) + add_box( + bm, + (px + sign * (POST_W / 2.0 + IRON_T / 2.0), 0.0, z), + (IRON_T, POST_W * 0.88, RAIL_Z * 1.40), + METAL_IDX, + ) + + xs = [v.co.x for v in bm.verts] + ys = [v.co.y for v in bm.verts] + zs = [v.co.z for v in bm.verts] + cy = 0.5 * (min(ys) + max(ys)) + zmin = min(zs) + for v in bm.verts: + v.co.y -= cy + v.co.z -= zmin + if v.co.z < 0.0: + v.co.z = 0.0 + + pack_uvs(bm) + bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces)) + for face in bm.faces: + face.smooth = False + me = bpy.data.meshes.new(name) + bm.to_mesh(me) + me.update() + for poly in me.polygons: + poly.use_smooth = False + finally: + bm.free() + out = bpy.data.objects.new(name, me) + bpy.context.collection.objects.link(out) + return out + + +def principled(name, color, metallic, roughness): + mat = bpy.data.materials.new(name) + mat.use_nodes = True + bsdf = mat.node_tree.nodes["Principled BSDF"] + bsdf.inputs["Base Color"].default_value = color + bsdf.inputs["Metallic"].default_value = metallic + bsdf.inputs["Roughness"].default_value = roughness + return mat + + +def assign_slots(obj, wood, metal): + # Do not materials.clear() — that resets polygon material_index to 0 + # on this Blender, which would drop metal faces onto wood. + mats = obj.data.materials + wanted = (wood, metal) + for i, mat in enumerate(wanted): + if i < len(mats): + mats[i] = mat + else: + mats.append(mat) + + +def world_bbox(obj): + corners = [obj.matrix_world @ Vector(c) for c in obj.bound_box] + xs = [c.x for c in corners] + ys = [c.y for c in corners] + zs = [c.z for c in corners] + return (min(xs), min(ys), min(zs), max(xs), max(ys), max(zs)) + + +def uv_stats(mesh): + uv = mesh.uv_layers.active + if uv is None: + return 0.0, 0.0, 1.0, 1.0, 0, 1.0 + data = uv.data + us = [loop.uv[0] for loop in data] + vs = [loop.uv[1] for loop in data] + aabbs = [] + for poly in mesh.polygons: + pu = [data[i].uv[0] for i in poly.loop_indices] + pv = [data[i].uv[1] for i in poly.loop_indices] + aabbs.append((min(pu), min(pv), max(pu), max(pv))) + overlap = 0.0 + for i in range(len(aabbs)): + a = aabbs[i] + for j in range(i + 1, len(aabbs)): + b = aabbs[j] + x0 = max(a[0], b[0]) + y0 = max(a[1], b[1]) + x1 = min(a[2], b[2]) + y1 = min(a[3], b[3]) + overlap += max(0.0, x1 - x0) * max(0.0, y1 - y0) + return min(us), min(vs), max(us), max(vs), overlap, len(aabbs) + + +def make_lod(obj, name, ratio, skip_decimate): + mesh = obj.data.copy() + lod = bpy.data.objects.new(name, mesh) + lod.matrix_world = obj.matrix_world.copy() + bpy.context.scene.collection.objects.link(lod) + if not skip_decimate and 0.0 < ratio < 1.0: + mod = lod.modifiers.new("DecimateBudget", "DECIMATE") + mod.decimate_type = "COLLAPSE" + mod.ratio = ratio + return lod + + +def convex_hull_collider(obj, name): + mesh = bpy.data.meshes.new(name) + bm = bmesh.new() + try: + bm.from_mesh(obj.data) + result = bmesh.ops.convex_hull(bm, input=list(bm.verts)) + interior = result.get("geom_interior") or [] + unused = result.get("geom_unused") or [] + if interior: + bmesh.ops.delete(bm, geom=interior, context="VERTS") + if unused: + bmesh.ops.delete(bm, geom=unused, context="VERTS") + bm.to_mesh(mesh) + mesh.update() + finally: + bm.free() + collider = bpy.data.objects.new(name, mesh) + bpy.context.collection.objects.link(collider) + collider.matrix_world = obj.matrix_world.copy() + return collider + + +def setup_bake_image(obj, target_mat, size=BAKE_RES): + if not obj.data.uv_layers: + return None, None + img = bpy.data.images.new("FenceNrm", size, size, alpha=True, float_buffer=False) + img.colorspace_settings.name = "Non-Color" + nodes = target_mat.node_tree.nodes + tex = nodes.new("ShaderNodeTexImage") + tex.image = img + nodes.active = tex + tex.select = True + obj.active_material_index = WOOD_IDX + return img, tex + + +def bake_normal(high, low): + scene = bpy.context.scene + scene.render.engine = "CYCLES" + scene.cycles.device = "CPU" + scene.cycles.samples = 1 + scene.cycles.use_denoising = False + deselect_all() + high.select_set(True) + low.select_set(True) + bpy.context.view_layer.objects.active = low + return bpy.ops.object.bake( + type="NORMAL", + use_selected_to_active=True, + cage_extrusion=CAGE_EXTRUSION, + use_cage=False, + normal_space="TANGENT", + margin=4, + margin_type="ADJACENT_FACES", + use_clear=True, + target="IMAGE_TEXTURES", + ) + + +def export_unity(path, objects): + deselect_all() + for ob in objects: + ob.select_set(True) + bpy.context.view_layer.objects.active = objects[0] + bpy.ops.export_scene.gltf( + filepath=path, + use_selection=True, + export_yup=True, + export_apply=True, + export_draco_mesh_compression_enable=False, + export_animations=False, + ) + + +def check(skip_decimate): + bpy.ops.wm.read_factory_settings(use_empty=True) + low = build_fence_mesh("FenceLow", bevel_offset=0.006, bevel_segments=2) + high = build_fence_mesh("FenceHigh", bevel_offset=0.006, bevel_segments=4) + wood = principled("FenceWood", (0.46, 0.24, 0.08, 1.0), 0.0, 0.55) + metal = principled("FenceIron", (0.11, 0.115, 0.13, 1.0), 1.0, 0.28) + assign_slots(low, wood, metal) + assign_slots(high, wood, metal) + + if low.data is None or len(low.data.polygons) < 6: + return fail("fence mesh did not build", 3), None, None, None, None, None + + base_tris = triangle_count(low.data) + mats = [s for s in low.data.materials if s is not None] + nmat = len(mats) + distinct_mats = len({id(s) for s in mats}) + idx_counts = {} + for poly in low.data.polygons: + idx_counts[poly.material_index] = idx_counts.get(poly.material_index, 0) + 1 + print(f"measured mat_index_counts={idx_counts}") + u0, v0, u1, v1, overlap, nfaces = uv_stats(low.data) + bb = world_bbox(low) + size_x = bb[3] - bb[0] + size_y = bb[4] - bb[1] + size_z = bb[5] - bb[2] + + img, tex = setup_bake_image(low, wood) + if img is None: + return fail("fence has no UV layer", 3), None, None, None, None, None + bake_result = bake_normal(high, low) + + lod1 = make_lod(low, "FenceLOD1", LOD1_TARGET, skip_decimate) + lod2 = make_lod(low, "FenceLOD2", LOD2_TARGET, skip_decimate) + bpy.context.view_layer.update() + lod1_tris = evaluated_triangle_count(lod1) + lod2_tris = evaluated_triangle_count(lod2) + r1 = lod1_tris / base_tris if base_tris else 0.0 + r2 = lod2_tris / base_tris if base_tris else 0.0 + + collider_src = build_fence_mesh("FenceColSrc", bevel_offset=0.0, bevel_segments=1) + collider = convex_hull_collider(collider_src, "FenceCollider") + bpy.data.objects.remove(collider_src, do_unlink=True) + col_tris = triangle_count(collider.data) + + export_path = os.path.join( + tempfile.gettempdir(), + f"bdt_fence_kit_{os.getpid()}.glb", + ) + if os.path.exists(export_path): + os.remove(export_path) + export_unity(export_path, [low, collider]) + export_size = os.path.getsize(export_path) if os.path.isfile(export_path) else 0 + + print(f"blender={tuple(bpy.app.version)} skip_decimate={skip_decimate}") + print( + f"measured base_tris={base_tris} lod1_tris={lod1_tris} " + f"lod2_tris={lod2_tris} r1={r1:.4f} r2={r2:.4f}" + ) + print( + f"measured nmat={nmat} uv=({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f}) " + f"overlap={overlap:.6f} nfaces={nfaces}" + ) + print( + f"measured bbox=({size_x:.4f},{size_y:.4f},{size_z:.4f}) " + f"outer={OUTER_SIZE} zmin={bb[2]:.4f}" + ) + print( + f"measured collider_tris={col_tris} bake={bake_result} " + f"bake_has_data={img.has_data} export_bytes={export_size}" + ) + + if not (BASE_TRIS_MIN <= base_tris <= BASE_TRIS_MAX): + return fail( + f"base tris {base_tris} not in [{BASE_TRIS_MIN}, {BASE_TRIS_MAX}]", + 4, + ), None, None, None, None, None + if nmat != MATERIAL_COUNT or distinct_mats != MATERIAL_COUNT: + return fail( + f"material slots {nmat} distinct {distinct_mats} != {MATERIAL_COUNT}", + 5, + ), None, None, None, None, None + if idx_counts.get(METAL_IDX, 0) < METAL_FACES_MIN: + return fail( + f"metal faces {idx_counts.get(METAL_IDX, 0)} < {METAL_FACES_MIN}", + 5, + ), None, None, None, None, None + if u0 < -UV_EPS or v0 < -UV_EPS or u1 > 1.0 + UV_EPS or v1 > 1.0 + UV_EPS: + return fail( + f"UVs outside 0..1: ({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f})", + 6, + ), None, None, None, None, None + if overlap > UV_OVERLAP_MAX: + return fail( + f"UV AABB overlap {overlap:.6f} > {UV_OVERLAP_MAX}", + 7, + ), None, None, None, None, None + if ( + abs(size_x - OUTER_SIZE[0]) > BBOX_TOL + or abs(size_y - OUTER_SIZE[1]) > BBOX_TOL + or abs(size_z - OUTER_SIZE[2]) > BBOX_TOL + ): + return fail( + f"bbox ({size_x:.4f},{size_y:.4f},{size_z:.4f}) " + f"off outer {OUTER_SIZE}", + 8, + ), None, None, None, None, None + if not (LOD1_RATIO_MIN <= r1 <= LOD1_RATIO_MAX): + return fail( + f"LOD1 ratio {r1:.4f} not in [{LOD1_RATIO_MIN}, {LOD1_RATIO_MAX}] " + "(--skip-decimate is the designed fail)", + 9, + ), None, None, None, None, None + if not (LOD2_RATIO_MIN <= r2 <= LOD2_RATIO_MAX): + return fail( + f"LOD2 ratio {r2:.4f} not in [{LOD2_RATIO_MIN}, {LOD2_RATIO_MAX}]", + 9, + ), None, None, None, None, None + if col_tris > COLLIDER_TRIS_MAX: + return fail( + f"collider tris {col_tris} > {COLLIDER_TRIS_MAX}", + 11, + ), None, None, None, None, None + if bake_result != {"FINISHED"} or not img.has_data: + return fail( + f"bake failed result={bake_result} has_data={img.has_data}", + 12, + ), None, None, None, None, None + if export_size <= 0: + return fail("export file missing or empty", 13), None, None, None, None, None + return 0, low, high, wood, tex, collider + + +def wire_normal(mat, tex): + nt = mat.node_tree + bsdf = nt.nodes["Principled BSDF"] + nrm = nt.nodes.new("ShaderNodeNormalMap") + nrm.inputs["Strength"].default_value = 1.0 + nt.links.new(tex.outputs["Color"], nrm.inputs["Color"]) + nt.links.new(nrm.outputs["Normal"], bsdf.inputs["Normal"]) + + +def render_still(low, wood, tex, path, engine): + scene = bpy.context.scene + wire_normal(wood, tex) + for ob in list(scene.objects): + if ob.type == "MESH" and ob != low: + ob.hide_render = True + ob.hide_viewport = True + + low.rotation_euler.z = math.radians(-16.0) + low.rotation_euler.x = math.radians(2.0) + + floor_me = bpy.data.meshes.new("Floor") + bm = bmesh.new() + try: + bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0) + bm.to_mesh(floor_me) + finally: + bm.free() + fmat = bpy.data.materials.new("Floor") + fmat.use_nodes = True + fb = fmat.node_tree.nodes["Principled BSDF"] + fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0) + fb.inputs["Roughness"].default_value = 0.7 + floor_me.materials.append(fmat) + floor = bpy.data.objects.new("Floor", floor_me) + scene.collection.objects.link(floor) + wall = bpy.data.objects.new("Wall", floor_me.copy()) + wall.location = (0.0, 8.5, 0.0) + wall.rotation_euler = (math.radians(90), 0.0, 0.0) + scene.collection.objects.link(wall) + + world = bpy.data.worlds.new("World") + world.use_nodes = True + world.node_tree.nodes["Background"].inputs["Color"].default_value = ( + 0.02, 0.021, 0.025, 1.0, + ) + scene.world = world + + def light(name, loc, energy, size, col, rot): + ld = bpy.data.lights.new(name, "AREA") + ld.energy = energy + ld.size = size + ld.color = col + ob = bpy.data.objects.new(name, ld) + ob.location = loc + ob.rotation_euler = tuple(math.radians(a) for a in rot) + scene.collection.objects.link(ob) + + light("Key", (-3.6, -5.0, 5.8), 680.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36)) + light("Fill", (5.0, -3.6, 2.6), 48.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50)) + light("Wedge", (2.4, 4.2, 4.1), 640.0, 5.5, (1.0, 0.70, 0.40), (-70, 0, 198)) + + cam_data = bpy.data.cameras.new("Cam") + cam_data.lens = 50.0 + cam = bpy.data.objects.new("Cam", cam_data) + cam.location = (2.50, -3.46, 1.95) + scene.collection.objects.link(cam) + aim = bpy.data.objects.new("Aim", None) + aim.location = (0.0, 0.0, 0.58) + scene.collection.objects.link(aim) + con = cam.constraints.new("TRACK_TO") + con.target = aim + con.track_axis = "TRACK_NEGATIVE_Z" + con.up_axis = "UP_Y" + scene.camera = cam + + scene.render.engine = "CYCLES" if engine == "cycles" else eevee_engine_id() + if engine == "cycles": + scene.cycles.samples = 32 + scene.cycles.device = "CPU" + else: + try: + scene.eevee.taa_render_samples = 64 + except AttributeError: + pass + scene.render.resolution_x = 1280 + scene.render.resolution_y = 720 + scene.render.image_settings.file_format = ( + "WEBP" if path.lower().endswith(".webp") else "PNG" + ) + if path.lower().endswith(".webp"): + scene.render.image_settings.quality = 90 + scene.render.filepath = path + scene.view_settings.view_transform = "Standard" + + fcode = gallery_framing.check_framing( + scene, cam, hero=[low], elements=[low], stage=[floor, wall], + ) + if fcode: + return fcode + bpy.ops.render.render(write_still=True) + if not (os.path.exists(path) and os.path.getsize(path) > 0): + return fail("render produced no file", 14) + return 0 + + +def main(): + argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else [] + p = argparse.ArgumentParser() + p.add_argument("--output", default=None) + p.add_argument("--engine", default="eevee", choices=("eevee", "cycles")) + p.add_argument( + "--skip-decimate", + action="store_true", + help="falsification: skip the LOD DECIMATE stage", + ) + args = p.parse_args(argv) + + code, low, _high, wood, tex, _col = check(args.skip_decimate) + if code: + return code + if args.output: + rcode = render_still(low, wood, tex, os.path.abspath(args.output), args.engine) + if rcode: + return rcode + print(f"rendered still {args.output}") + print("fence-kit OK") + return 0 + + +if __name__ == "__main__": + try: + sys.exit(main()) + except Exception as e: + traceback.print_exc() + print(f"FATAL: {e}", file=sys.stderr) + sys.exit(1) diff --git a/showcase/fence-kit/preview.webp b/showcase/fence-kit/preview.webp new file mode 100644 index 0000000..3957412 Binary files /dev/null and b/showcase/fence-kit/preview.webp differ diff --git a/showcase/gallery.json b/showcase/gallery.json index 981c2e6..5eb3818 100644 --- a/showcase/gallery.json +++ b/showcase/gallery.json @@ -88,6 +88,30 @@ "mesh", "export" ] + }, + { + "name": "terrain-scatter", + "dir": "showcase/terrain-scatter", + "teaches": "A Geometry Nodes hill tile with masonry scatter through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.", + "witnessesFix": "Recomputed: 1194 tris, two materials with 486 stone faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.800×1.800×0.655 m, LOD ratios in band, convex collider 52 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.", + "hero": "docs/gallery/assets/terrain-scatter-hero.webp", + "preview": "showcase/terrain-scatter/preview.webp", + "tags": [ + "mesh", + "export" + ] + }, + { + "name": "fence-kit", + "dir": "showcase/fence-kit", + "teaches": "A procedural post-and-rail fence section through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.", + "witnessesFix": "Recomputed: 1212 tris, two materials with 120 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.642×0.157×1.235 m, LOD ratios in band, convex collider 62 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.", + "hero": "docs/gallery/assets/fence-kit-hero.webp", + "preview": "showcase/fence-kit/preview.webp", + "tags": [ + "mesh", + "export" + ] } ] } diff --git a/showcase/terrain-scatter/README.md b/showcase/terrain-scatter/README.md new file mode 100644 index 0000000..499afe1 --- /dev/null +++ b/showcase/terrain-scatter/README.md @@ -0,0 +1,75 @@ +# Terrain scatter + +A showcase piece, not an example. Geometry Nodes sine-hill Mesh Grid +with an Index-jittered Instance-on-Points scatter, realized cubes +replaced by bevelled masonry, then the shipped pipeline: unique-cell +UVs, Cycles high-to-low normal bake, LOD chain, convex collider, +Unity glTF export. + +It asserts **budget conformance** of the generated result. It does not +witness an API contract. "It rendered without error" is not a check. + +**Composes** skills `geometry-nodes-python`, `mesh-editing-and-bmesh`, +`bake-high-to-low`, `depsgraph-and-evaluated-data`, +`engine-export-presets`, and snippets `bake_normal_high_to_low.py`, +`setup_bake_target_image.py`, `lod_chain.py` / `decimate_to_budget.py`, +`convex_hull_collider.py`, `export_preset_unity.py` (helpers copied, +not imported as a package). + +## Budgets + +Declared as named constants; every gate **recomputes** from the mesh, +materials, UVs, evaluated LOD, collider, or export file. + +| Axis | Declared | Measured (4.5.11 / 5.1.2 / 5.2.1) | +| --- | --- | --- | +| Base triangles | 1150–1250 | 1194 / 1194 / 1194 | +| LOD1 ratio | 0.32–0.62 of base | 0.4992 / 0.4992 / 0.4992 | +| LOD2 ratio | 0.10–0.35 of base | 0.2194 / 0.2194 / 0.2194 | +| Materials | exactly 2 distinct, ≥24 stone faces | 2 slots, 486 stone | +| UVs | in `0..1`, AABB overlap ≤ 1e-5 | in range, overlap 0 | +| Outer AABB | (1.800, 1.800, 0.655) m ± 0.01 | (1.8000, 1.8000, 0.6554), zmin 0 | +| Collider tris | ≤ 80 | 52 | +| Export | written, size > 0 | 90704 / 90704 / 90696 bytes | + +DECIMATE COLLAPSE triangle counts are **not** guaranteed identical across +series — the gate is a ratio band, not an exact count. This mesh happened +to match on 4.5.11 / 5.1.2 / 5.2.1. Bake pixels are stochastic; the gate +is `has_data` plus operator `FINISHED`, not byte-identity. Construction +uses no RNG. glTF byte size may differ by a few bytes across series. + +`--skip-decimate` skips the LOD DECIMATE stage so LOD1 ratio is 1.0 and +exit 9 fires. That is the named budget the falsifier violates. + +## Run + +```bash +blender --background --python terrain_scatter.py -- +blender --background --python terrain_scatter.py -- --skip-decimate +blender --background --python terrain_scatter.py -- --output terrain.png +``` + +Smoke does not pass `--output` or `--skip-decimate`. + +## Exit codes + +File-local. `9` is a valid check code. `10` is reserved for +`gallery_framing.check_framing` on the `--output` path. + +| Code | Meaning | +| --- | --- | +| 0 | Success | +| 1 | Uncaught exception (FATAL wrapper) | +| 2 | argparse / usage | +| 3 | Mesh did not build / no UV layer | +| 4 | Base triangle count outside range | +| 5 | Material count ≠ 2 distinct slots, or stone faces missing | +| 6 | UVs outside 0..1 | +| 7 | UV AABB overlap above tolerance | +| 8 | World AABB off declared outer size | +| 9 | LOD ratio band (`--skip-decimate` lands here) | +| 10 | Framing gate (render path only) | +| 11 | Collider triangle count above ceiling | +| 12 | Bake did not finish or image has no data | +| 13 | Export file missing or empty | +| 14 | `--output` produced no file | diff --git a/showcase/terrain-scatter/preview.webp b/showcase/terrain-scatter/preview.webp new file mode 100644 index 0000000..0ff73df Binary files /dev/null and b/showcase/terrain-scatter/preview.webp differ diff --git a/showcase/terrain-scatter/terrain_scatter.py b/showcase/terrain-scatter/terrain_scatter.py new file mode 100644 index 0000000..949e762 --- /dev/null +++ b/showcase/terrain-scatter/terrain_scatter.py @@ -0,0 +1,888 @@ +"""Game-ready GN terrain scatter — a showcase piece, not an example. + +Asserts budget conformance of a Geometry Nodes hill grid with instanced +masonry rocks after composing shipped pipeline pieces: GN construction, +UVs, two materials, high-to-low normal bake, LOD chain, convex collider, +Unity glTF export. + +Budgets are declared below and recomputed from the generated result. +They are not API-contract witnesses. ``--skip-decimate`` skips the LOD +DECIMATE stage so the LOD-ratio budget fails. + +No RNG. Hills are a closed-form sine product; scatter is an Index-jittered +instance grid. Realized cubes are replaced with bevelled lumped boxes +(campfire/well masonry, not icospheres). DECIMATE COLLAPSE triangle +counts are not byte-identical across Blender versions — the LOD gate is +a ratio band, not an exact count. + + blender --background --python terrain_scatter.py -- + blender --background --python terrain_scatter.py -- --skip-decimate + blender --background --python terrain_scatter.py -- --output terrain.png +""" +import argparse +import math +import os +import sys +import tempfile +import traceback + +import bmesh +import bpy +from mathutils import Euler, Vector + +_REPO = os.path.abspath( + os.path.join(os.path.dirname(os.path.abspath(__file__)), os.pardir, os.pardir) +) +sys.path.insert(0, os.path.join(_REPO, "examples")) +sys.dont_write_bytecode = True +import gallery_framing # noqa: E402 + +PATCH = 1.80 +FREQ = 2.2 +AMP = 0.16 +ROCK_SIZE = (0.22, 0.17, 0.13) +ROCK_GRID = 3 +ROCK_SPAN = 1.15 +SLAB_LIFT = 0.10 + +BBOX_TOL = 0.01 +OUTER_SIZE = (1.800, 1.800, 0.655) +BASE_TRIS_MIN = 1150 +BASE_TRIS_MAX = 1250 +LOD1_RATIO_MIN = 0.32 +LOD1_RATIO_MAX = 0.62 +LOD2_RATIO_MIN = 0.10 +LOD2_RATIO_MAX = 0.35 +LOD1_TARGET = 0.50 +LOD2_TARGET = 0.22 +MATERIAL_COUNT = 2 +UV_EPS = 1e-4 +UV_OVERLAP_MAX = 1e-5 +COLLIDER_TRIS_MAX = 80 +BAKE_RES = 256 +CAGE_EXTRUSION = 0.08 +STONE_FACES_MIN = 24 + +DIRT_IDX = 0 +STONE_IDX = 1 + + +def eevee_engine_id(): + return "BLENDER_EEVEE" if bpy.app.version >= (5, 0, 0) else "BLENDER_EEVEE_NEXT" + + +def fail(msg, code): + print(f"ERROR: {msg}", file=sys.stderr) + return code + + +def triangle_count(mesh): + mesh.calc_loop_triangles() + return len(mesh.loop_triangles) + + +def evaluated_triangle_count(obj): + depsgraph = bpy.context.evaluated_depsgraph_get() + eval_obj = obj.evaluated_get(depsgraph) + eval_mesh = eval_obj.to_mesh() + try: + eval_mesh.calc_loop_triangles() + return len(eval_mesh.loop_triangles) + finally: + eval_obj.to_mesh_clear() + + +def deselect_all(): + for ob in list(bpy.context.view_layer.objects): + if ob is None: + continue + ob.select_set(False) + + +def add_box(bm, loc, scale, mat_idx, euler=(0.0, 0.0, 0.0)): + geo = bmesh.ops.create_cube(bm, size=1.0) + verts = geo["verts"] + rot = Euler(euler).to_matrix() + origin = Vector(loc) + for v in verts: + p = Vector((v.co.x * scale[0], v.co.y * scale[1], v.co.z * scale[2])) + v.co = rot @ p + origin + faces = {f for v in verts for f in v.link_faces} + for f in faces: + f.material_index = mat_idx + return verts + + +def pack_uvs(bm, margin=0.08): + uv = bm.loops.layers.uv.new("UVMap") + faces = list(bm.faces) + n = len(faces) + cols = max(1, math.ceil(math.sqrt(n))) + rows = max(1, math.ceil(n / cols)) + cell_w = 1.0 / cols + cell_h = 1.0 / rows + pad_u = margin * cell_w * 0.5 + pad_v = margin * cell_h * 0.5 + usable_w = cell_w - 2.0 * pad_u + usable_h = cell_h - 2.0 * pad_v + for i, face in enumerate(faces): + col = i % cols + row = i // cols + nrm = face.normal + ax = abs(nrm.x) + ay = abs(nrm.y) + az = abs(nrm.z) + coords = [] + for loop in face.loops: + co = loop.vert.co + if az >= ax and az >= ay: + coords.append((co.x, co.y)) + elif ax >= ay: + coords.append((co.y, co.z)) + else: + coords.append((co.x, co.z)) + xs = [c[0] for c in coords] + ys = [c[1] for c in coords] + minx, maxx = min(xs), max(xs) + miny, maxy = min(ys), max(ys) + dx = max(maxx - minx, 1e-8) + dy = max(maxy - miny, 1e-8) + origin_u = col * cell_w + pad_u + origin_v = row * cell_h + pad_v + for loop, (x, y) in zip(face.loops, coords): + loop[uv].uv = ( + origin_u + (x - minx) / dx * usable_w, + origin_v + (y - miny) / dy * usable_h, + ) + + +def hill_z_socket(tree, freq, amp): + pos = tree.nodes.new("GeometryNodeInputPosition") + sep = tree.nodes.new("ShaderNodeSeparateXYZ") + tree.links.new(pos.outputs["Position"], sep.inputs[0]) + mx = tree.nodes.new("ShaderNodeMath") + mx.operation = "MULTIPLY" + mx.inputs[1].default_value = freq + my = tree.nodes.new("ShaderNodeMath") + my.operation = "MULTIPLY" + my.inputs[1].default_value = freq + tree.links.new(sep.outputs["X"], mx.inputs[0]) + tree.links.new(sep.outputs["Y"], my.inputs[0]) + sine = tree.nodes.new("ShaderNodeMath") + sine.operation = "SINE" + cose = tree.nodes.new("ShaderNodeMath") + cose.operation = "COSINE" + tree.links.new(mx.outputs[0], sine.inputs[0]) + tree.links.new(my.outputs[0], cose.inputs[0]) + prod = tree.nodes.new("ShaderNodeMath") + prod.operation = "MULTIPLY" + tree.links.new(sine.outputs[0], prod.inputs[0]) + tree.links.new(cose.outputs[0], prod.inputs[1]) + add1 = tree.nodes.new("ShaderNodeMath") + add1.operation = "ADD" + add1.inputs[1].default_value = 1.0 + tree.links.new(prod.outputs[0], add1.inputs[0]) + sc = tree.nodes.new("ShaderNodeMath") + sc.operation = "MULTIPLY" + sc.inputs[1].default_value = amp + tree.links.new(add1.outputs[0], sc.inputs[0]) + return sc.outputs[0] + + +def build_scatter_tree(verts, dirt, stone): + tree = bpy.data.node_groups.new("TerrainScatter", "GeometryNodeTree") + tree.interface.new_socket( + name="Geometry", in_out="OUTPUT", socket_type="NodeSocketGeometry", + ) + go = tree.nodes.new("NodeGroupOutput") + + hill = hill_z_socket(tree, FREQ, AMP) + off = tree.nodes.new("ShaderNodeCombineXYZ") + tree.links.new(hill, off.inputs["Z"]) + + grid = tree.nodes.new("GeometryNodeMeshGrid") + grid.inputs["Size X"].default_value = PATCH + grid.inputs["Size Y"].default_value = PATCH + grid.inputs["Vertices X"].default_value = verts + grid.inputs["Vertices Y"].default_value = verts + set_pos = tree.nodes.new("GeometryNodeSetPosition") + tree.links.new(grid.outputs["Mesh"], set_pos.inputs["Geometry"]) + tree.links.new(off.outputs["Vector"], set_pos.inputs["Offset"]) + lift = tree.nodes.new("GeometryNodeTransform") + lift.inputs["Translation"].default_value = (0.0, 0.0, SLAB_LIFT) + tree.links.new(set_pos.outputs["Geometry"], lift.inputs["Geometry"]) + shade_t = tree.nodes.new("GeometryNodeSetShadeSmooth") + shade_t.inputs["Shade Smooth"].default_value = False + tree.links.new(lift.outputs["Geometry"], shade_t.inputs["Geometry"]) + sm_d = tree.nodes.new("GeometryNodeSetMaterial") + sm_d.inputs["Material"].default_value = dirt + tree.links.new(shade_t.outputs["Geometry"], sm_d.inputs["Geometry"]) + + pts = tree.nodes.new("GeometryNodeMeshGrid") + pts.inputs["Size X"].default_value = ROCK_SPAN + pts.inputs["Size Y"].default_value = ROCK_SPAN + pts.inputs["Vertices X"].default_value = ROCK_GRID + pts.inputs["Vertices Y"].default_value = ROCK_GRID + idx = tree.nodes.new("GeometryNodeInputIndex") + jx = tree.nodes.new("ShaderNodeMath") + jx.operation = "MULTIPLY" + jx.inputs[1].default_value = 1.73 + tree.links.new(idx.outputs["Index"], jx.inputs[0]) + jxs = tree.nodes.new("ShaderNodeMath") + jxs.operation = "SINE" + tree.links.new(jx.outputs[0], jxs.inputs[0]) + jxm = tree.nodes.new("ShaderNodeMath") + jxm.operation = "MULTIPLY" + jxm.inputs[1].default_value = 0.09 + tree.links.new(jxs.outputs[0], jxm.inputs[0]) + jy = tree.nodes.new("ShaderNodeMath") + jy.operation = "MULTIPLY" + jy.inputs[1].default_value = 2.19 + tree.links.new(idx.outputs["Index"], jy.inputs[0]) + jyc = tree.nodes.new("ShaderNodeMath") + jyc.operation = "COSINE" + tree.links.new(jy.outputs[0], jyc.inputs[0]) + jym = tree.nodes.new("ShaderNodeMath") + jym.operation = "MULTIPLY" + jym.inputs[1].default_value = 0.09 + tree.links.new(jyc.outputs[0], jym.inputs[0]) + extra = tree.nodes.new("ShaderNodeMath") + extra.operation = "ADD" + extra.inputs[1].default_value = SLAB_LIFT + tree.links.new(hill, extra.inputs[0]) + jitter = tree.nodes.new("ShaderNodeCombineXYZ") + tree.links.new(jxm.outputs[0], jitter.inputs["X"]) + tree.links.new(jym.outputs[0], jitter.inputs["Y"]) + tree.links.new(extra.outputs[0], jitter.inputs["Z"]) + set_pts = tree.nodes.new("GeometryNodeSetPosition") + tree.links.new(pts.outputs["Mesh"], set_pts.inputs["Geometry"]) + tree.links.new(jitter.outputs["Vector"], set_pts.inputs["Offset"]) + + cube = tree.nodes.new("GeometryNodeMeshCube") + cube.inputs["Size"].default_value = ROCK_SIZE + iop = tree.nodes.new("GeometryNodeInstanceOnPoints") + tree.links.new(set_pts.outputs["Geometry"], iop.inputs["Points"]) + tree.links.new(cube.outputs["Mesh"], iop.inputs["Instance"]) + + ang = tree.nodes.new("ShaderNodeMath") + ang.operation = "MULTIPLY" + ang.inputs[1].default_value = 0.67 + tree.links.new(idx.outputs["Index"], ang.inputs[0]) + rot = tree.nodes.new("ShaderNodeCombineXYZ") + tree.links.new(ang.outputs[0], rot.inputs["Z"]) + tree.links.new(rot.outputs["Vector"], iop.inputs["Rotation"]) + + mod = tree.nodes.new("ShaderNodeMath") + mod.operation = "MODULO" + mod.inputs[1].default_value = 3.0 + tree.links.new(idx.outputs["Index"], mod.inputs[0]) + div = tree.nodes.new("ShaderNodeMath") + div.operation = "DIVIDE" + div.inputs[1].default_value = 3.0 + tree.links.new(mod.outputs[0], div.inputs[0]) + mul_s = tree.nodes.new("ShaderNodeMath") + mul_s.operation = "MULTIPLY" + mul_s.inputs[1].default_value = 0.22 + tree.links.new(div.outputs[0], mul_s.inputs[0]) + add_s = tree.nodes.new("ShaderNodeMath") + add_s.operation = "ADD" + add_s.inputs[1].default_value = 0.84 + tree.links.new(mul_s.outputs[0], add_s.inputs[0]) + scl = tree.nodes.new("ShaderNodeCombineXYZ") + tree.links.new(add_s.outputs[0], scl.inputs["X"]) + tree.links.new(add_s.outputs[0], scl.inputs["Y"]) + tree.links.new(add_s.outputs[0], scl.inputs["Z"]) + tree.links.new(scl.outputs["Vector"], iop.inputs["Scale"]) + + realize = tree.nodes.new("GeometryNodeRealizeInstances") + tree.links.new(iop.outputs["Instances"], realize.inputs["Geometry"]) + sm_s = tree.nodes.new("GeometryNodeSetMaterial") + sm_s.inputs["Material"].default_value = stone + tree.links.new(realize.outputs["Geometry"], sm_s.inputs["Geometry"]) + + join = tree.nodes.new("GeometryNodeJoinGeometry") + tree.links.new(sm_d.outputs["Geometry"], join.inputs[0]) + tree.links.new(sm_s.outputs["Geometry"], join.inputs[0]) + shade = tree.nodes.new("GeometryNodeSetShadeSmooth") + shade.inputs["Shade Smooth"].default_value = False + tree.links.new(join.outputs["Geometry"], shade.inputs["Geometry"]) + tree.links.new(shade.outputs["Geometry"], go.inputs["Geometry"]) + return tree + + +def eval_to_mesh(obj, name): + bpy.context.view_layer.update() + dg = bpy.context.evaluated_depsgraph_get() + ev = obj.evaluated_get(dg) + em = ev.to_mesh() + try: + me = bpy.data.meshes.new(name) + me.from_pydata( + [tuple(v.co) for v in em.vertices], + [], + [tuple(p.vertices) for p in em.polygons], + ) + src_idx = [p.material_index for p in em.polygons] + me.update() + for poly, idx in zip(me.polygons, src_idx): + poly.material_index = idx + finally: + ev.to_mesh_clear() + return me + + +def slabify(bm, floor_z=0.0): + bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces)) + boundary = [e for e in bm.edges if e.is_boundary] + if not boundary: + return + ret = bmesh.ops.extrude_edge_only(bm, edges=boundary) + verts = [g for g in ret["geom"] if isinstance(g, bmesh.types.BMVert)] + for v in verts: + v.co.z = floor_z + bottom = [ + e for e in bm.edges + if e.is_boundary + and abs(e.verts[0].co.z - floor_z) < 1e-5 + and abs(e.verts[1].co.z - floor_z) < 1e-5 + ] + if bottom: + try: + bmesh.ops.edgeloop_fill(bm, edges=bottom) + except Exception: + bmesh.ops.contextual_create(bm, geom=bottom) + for f in bm.faces: + if f.material_index not in (DIRT_IDX, STONE_IDX): + f.material_index = DIRT_IDX + + +def masonry_from_cubes(bm, lump, bevel_offset, bevel_segments): + stone_faces = [f for f in bm.faces if f.material_index == STONE_IDX] + visited = set() + islands = [] + for face in stone_faces: + if face in visited: + continue + stack = [face] + island = [] + while stack: + cur = stack.pop() + if cur in visited: + continue + visited.add(cur) + island.append(cur) + for edge in cur.edges: + for other in edge.link_faces: + if other.material_index == STONE_IDX and other not in visited: + stack.append(other) + islands.append(island) + + specs = [] + for island in islands: + verts = {v for f in island for v in f.verts} + xs = [v.co.x for v in verts] + ys = [v.co.y for v in verts] + zs = [v.co.z for v in verts] + cx = 0.5 * (min(xs) + max(xs)) + cy = 0.5 * (min(ys) + max(ys)) + cz = 0.5 * (min(zs) + max(zs)) + z0 = min(zs) + sx = 0.17 + 0.04 * math.sin(cx * 8.1) + sy = 0.15 + 0.03 * math.cos(cy * 6.4) + sz = 0.20 + 0.05 * math.sin(cx * 4.2 + cy * 3.1) + ex = 0.38 * math.sin(cx * 5.1) + ey = 0.30 * math.cos(cy * 4.3) + ez = cx * 3.7 + cy * 2.1 + cz = z0 + sz * 0.30 + specs.append((cx, cy, cz, sx, sy, sz, ex, ey, ez)) + + if stone_faces: + bmesh.ops.delete(bm, geom=stone_faces, context="FACES") + loose = [v for v in bm.verts if not v.link_faces] + if loose: + bmesh.ops.delete(bm, geom=loose, context="VERTS") + + for cx, cy, cz, sx, sy, sz, ex, ey, ez in specs: + verts = add_box( + bm, + (cx, cy, cz), + (sx, sy, sz), + STONE_IDX, + euler=(ex, ey, ez), + ) + if bevel_offset > 0.0: + edges = list({e for v in verts for e in v.link_edges}) + if edges: + ret = bmesh.ops.bevel( + bm, + geom=edges, + offset=bevel_offset, + segments=bevel_segments, + profile=0.5, + affect="EDGES", + clamp_overlap=True, + ) + for f in ret.get("faces") or []: + f.material_index = STONE_IDX + + +def build_terrain_mesh(name, grid_verts, lump, bevel_offset, bevel_segments, dirt, stone): + carrier = bpy.data.meshes.new(name + "Carrier") + carrier.vertices.add(1) + obj = bpy.data.objects.new(name + "GN", carrier) + bpy.context.collection.objects.link(obj) + tree = build_scatter_tree(grid_verts, dirt, stone) + mod = obj.modifiers.new("terrain_scatter", "NODES") + mod.node_group = tree + realized = eval_to_mesh(obj, name + "Eval") + bpy.data.objects.remove(obj, do_unlink=True) + + bm = bmesh.new() + try: + bm.from_mesh(realized) + bm.verts.ensure_lookup_table() + bm.edges.ensure_lookup_table() + bm.faces.ensure_lookup_table() + slabify(bm, floor_z=0.0) + bm.verts.ensure_lookup_table() + bm.faces.ensure_lookup_table() + masonry_from_cubes(bm, lump, bevel_offset, bevel_segments) + xs = [v.co.x for v in bm.verts] + ys = [v.co.y for v in bm.verts] + zs = [v.co.z for v in bm.verts] + cx = 0.5 * (min(xs) + max(xs)) + cy = 0.5 * (min(ys) + max(ys)) + zmin = min(zs) + for v in bm.verts: + v.co.x -= cx + v.co.y -= cy + v.co.z -= zmin + if v.co.z < 0.0: + v.co.z = 0.0 + pack_uvs(bm) + bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces)) + for face in bm.faces: + face.smooth = False + me = bpy.data.meshes.new(name) + bm.to_mesh(me) + me.update() + for poly in me.polygons: + poly.use_smooth = False + finally: + bm.free() + out = bpy.data.objects.new(name, me) + bpy.context.collection.objects.link(out) + return out + + +def principled(name, color, metallic, roughness): + mat = bpy.data.materials.new(name) + mat.use_nodes = True + bsdf = mat.node_tree.nodes["Principled BSDF"] + bsdf.inputs["Base Color"].default_value = color + bsdf.inputs["Metallic"].default_value = metallic + bsdf.inputs["Roughness"].default_value = roughness + return mat + + +def assign_slots(obj, dirt, stone): + # Do not materials.clear() — that resets polygon material_index to 0 + # on this Blender, which would drop stone faces onto dirt. + mats = obj.data.materials + wanted = (dirt, stone) + for i, mat in enumerate(wanted): + if i < len(mats): + mats[i] = mat + else: + mats.append(mat) + + +def world_bbox(obj): + corners = [obj.matrix_world @ Vector(c) for c in obj.bound_box] + xs = [c.x for c in corners] + ys = [c.y for c in corners] + zs = [c.z for c in corners] + return (min(xs), min(ys), min(zs), max(xs), max(ys), max(zs)) + + +def uv_stats(mesh): + uv = mesh.uv_layers.active + if uv is None: + return 0.0, 0.0, 1.0, 1.0, 0, 1.0 + data = uv.data + us = [loop.uv[0] for loop in data] + vs = [loop.uv[1] for loop in data] + aabbs = [] + for poly in mesh.polygons: + pu = [data[i].uv[0] for i in poly.loop_indices] + pv = [data[i].uv[1] for i in poly.loop_indices] + aabbs.append((min(pu), min(pv), max(pu), max(pv))) + overlap = 0.0 + for i in range(len(aabbs)): + a = aabbs[i] + for j in range(i + 1, len(aabbs)): + b = aabbs[j] + x0 = max(a[0], b[0]) + y0 = max(a[1], b[1]) + x1 = min(a[2], b[2]) + y1 = min(a[3], b[3]) + overlap += max(0.0, x1 - x0) * max(0.0, y1 - y0) + return min(us), min(vs), max(us), max(vs), overlap, len(aabbs) + + +def make_lod(obj, name, ratio, skip_decimate): + mesh = obj.data.copy() + lod = bpy.data.objects.new(name, mesh) + lod.matrix_world = obj.matrix_world.copy() + bpy.context.scene.collection.objects.link(lod) + if not skip_decimate and 0.0 < ratio < 1.0: + mod = lod.modifiers.new("DecimateBudget", "DECIMATE") + mod.decimate_type = "COLLAPSE" + mod.ratio = ratio + return lod + + +def convex_hull_collider(obj, name): + mesh = bpy.data.meshes.new(name) + bm = bmesh.new() + try: + bm.from_mesh(obj.data) + result = bmesh.ops.convex_hull(bm, input=list(bm.verts)) + interior = result.get("geom_interior") or [] + unused = result.get("geom_unused") or [] + if interior: + bmesh.ops.delete(bm, geom=interior, context="VERTS") + if unused: + bmesh.ops.delete(bm, geom=unused, context="VERTS") + bm.to_mesh(mesh) + mesh.update() + finally: + bm.free() + collider = bpy.data.objects.new(name, mesh) + bpy.context.collection.objects.link(collider) + collider.matrix_world = obj.matrix_world.copy() + return collider + + +def setup_bake_image(obj, target_mat, size=BAKE_RES): + if not obj.data.uv_layers: + return None, None + img = bpy.data.images.new("TerrainNrm", size, size, alpha=True, float_buffer=False) + img.colorspace_settings.name = "Non-Color" + nodes = target_mat.node_tree.nodes + tex = nodes.new("ShaderNodeTexImage") + tex.image = img + nodes.active = tex + tex.select = True + obj.active_material_index = DIRT_IDX + return img, tex + + +def bake_normal(high, low): + scene = bpy.context.scene + scene.render.engine = "CYCLES" + scene.cycles.device = "CPU" + scene.cycles.samples = 1 + scene.cycles.use_denoising = False + deselect_all() + high.select_set(True) + low.select_set(True) + bpy.context.view_layer.objects.active = low + return bpy.ops.object.bake( + type="NORMAL", + use_selected_to_active=True, + cage_extrusion=CAGE_EXTRUSION, + use_cage=False, + normal_space="TANGENT", + margin=4, + margin_type="ADJACENT_FACES", + use_clear=True, + target="IMAGE_TEXTURES", + ) + + +def export_unity(path, objects): + deselect_all() + for ob in objects: + ob.select_set(True) + bpy.context.view_layer.objects.active = objects[0] + bpy.ops.export_scene.gltf( + filepath=path, + use_selection=True, + export_yup=True, + export_apply=True, + export_draco_mesh_compression_enable=False, + export_animations=False, + ) + + +def check(skip_decimate): + bpy.ops.wm.read_factory_settings(use_empty=True) + dirt = principled("TerrainDirt", (0.30, 0.17, 0.07, 1.0), 0.0, 0.90) + stone = principled("TerrainStone", (0.56, 0.53, 0.48, 1.0), 0.0, 0.76) + low = build_terrain_mesh("TerrainLow", 9, 0.10, 0.022, 2, dirt, stone) + high = build_terrain_mesh("TerrainHigh", 13, 0.10, 0.022, 4, dirt, stone) + assign_slots(low, dirt, stone) + assign_slots(high, dirt, stone) + + if low.data is None or len(low.data.polygons) < 6: + return fail("terrain mesh did not build", 3), None, None, None, None, None + + base_tris = triangle_count(low.data) + mats = [s for s in low.data.materials if s is not None] + nmat = len(mats) + distinct_mats = len({id(s) for s in mats}) + idx_counts = {} + for poly in low.data.polygons: + idx_counts[poly.material_index] = idx_counts.get(poly.material_index, 0) + 1 + print(f"measured mat_index_counts={idx_counts}") + u0, v0, u1, v1, overlap, nfaces = uv_stats(low.data) + bb = world_bbox(low) + size_x = bb[3] - bb[0] + size_y = bb[4] - bb[1] + size_z = bb[5] - bb[2] + + img, tex = setup_bake_image(low, dirt) + if img is None: + return fail("terrain has no UV layer", 3), None, None, None, None, None + bake_result = bake_normal(high, low) + + lod1 = make_lod(low, "TerrainLOD1", LOD1_TARGET, skip_decimate) + lod2 = make_lod(low, "TerrainLOD2", LOD2_TARGET, skip_decimate) + bpy.context.view_layer.update() + lod1_tris = evaluated_triangle_count(lod1) + lod2_tris = evaluated_triangle_count(lod2) + r1 = lod1_tris / base_tris if base_tris else 0.0 + r2 = lod2_tris / base_tris if base_tris else 0.0 + + collider_src = build_terrain_mesh( + "TerrainColSrc", 9, 0.0, 0.0, 1, dirt, stone + ) + collider = convex_hull_collider(collider_src, "TerrainCollider") + bpy.data.objects.remove(collider_src, do_unlink=True) + col_tris = triangle_count(collider.data) + + export_path = os.path.join( + tempfile.gettempdir(), + f"bdt_terrain_scatter_{os.getpid()}.glb", + ) + if os.path.exists(export_path): + os.remove(export_path) + export_unity(export_path, [low, collider]) + export_size = os.path.getsize(export_path) if os.path.isfile(export_path) else 0 + + print(f"blender={tuple(bpy.app.version)} skip_decimate={skip_decimate}") + print( + f"measured base_tris={base_tris} lod1_tris={lod1_tris} " + f"lod2_tris={lod2_tris} r1={r1:.4f} r2={r2:.4f}" + ) + print( + f"measured nmat={nmat} uv=({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f}) " + f"overlap={overlap:.6f} nfaces={nfaces}" + ) + print( + f"measured bbox=({size_x:.4f},{size_y:.4f},{size_z:.4f}) " + f"outer={OUTER_SIZE} zmin={bb[2]:.4f}" + ) + print( + f"measured collider_tris={col_tris} bake={bake_result} " + f"bake_has_data={img.has_data} export_bytes={export_size}" + ) + + if not (BASE_TRIS_MIN <= base_tris <= BASE_TRIS_MAX): + return fail( + f"base tris {base_tris} not in [{BASE_TRIS_MIN}, {BASE_TRIS_MAX}]", + 4, + ), None, None, None, None, None + if nmat != MATERIAL_COUNT or distinct_mats != MATERIAL_COUNT: + return fail( + f"material slots {nmat} distinct {distinct_mats} != {MATERIAL_COUNT}", + 5, + ), None, None, None, None, None + if idx_counts.get(STONE_IDX, 0) < STONE_FACES_MIN: + return fail( + f"stone faces {idx_counts.get(STONE_IDX, 0)} < {STONE_FACES_MIN}", + 5, + ), None, None, None, None, None + if u0 < -UV_EPS or v0 < -UV_EPS or u1 > 1.0 + UV_EPS or v1 > 1.0 + UV_EPS: + return fail( + f"UVs outside 0..1: ({u0:.4f},{v0:.4f})-({u1:.4f},{v1:.4f})", + 6, + ), None, None, None, None, None + if overlap > UV_OVERLAP_MAX: + return fail( + f"UV AABB overlap {overlap:.6f} > {UV_OVERLAP_MAX}", + 7, + ), None, None, None, None, None + if ( + abs(size_x - OUTER_SIZE[0]) > BBOX_TOL + or abs(size_y - OUTER_SIZE[1]) > BBOX_TOL + or abs(size_z - OUTER_SIZE[2]) > BBOX_TOL + ): + return fail( + f"bbox ({size_x:.4f},{size_y:.4f},{size_z:.4f}) " + f"off outer {OUTER_SIZE}", + 8, + ), None, None, None, None, None + if not (LOD1_RATIO_MIN <= r1 <= LOD1_RATIO_MAX): + return fail( + f"LOD1 ratio {r1:.4f} not in [{LOD1_RATIO_MIN}, {LOD1_RATIO_MAX}] " + "(--skip-decimate is the designed fail)", + 9, + ), None, None, None, None, None + if not (LOD2_RATIO_MIN <= r2 <= LOD2_RATIO_MAX): + return fail( + f"LOD2 ratio {r2:.4f} not in [{LOD2_RATIO_MIN}, {LOD2_RATIO_MAX}]", + 9, + ), None, None, None, None, None + if col_tris > COLLIDER_TRIS_MAX: + return fail( + f"collider tris {col_tris} > {COLLIDER_TRIS_MAX}", + 11, + ), None, None, None, None, None + if bake_result != {"FINISHED"} or not img.has_data: + return fail( + f"bake failed result={bake_result} has_data={img.has_data}", + 12, + ), None, None, None, None, None + if export_size <= 0: + return fail("export file missing or empty", 13), None, None, None, None, None + return 0, low, high, dirt, tex, collider + + +def wire_normal(mat, tex): + nt = mat.node_tree + bsdf = nt.nodes["Principled BSDF"] + nrm = nt.nodes.new("ShaderNodeNormalMap") + nrm.inputs["Strength"].default_value = 1.0 + nt.links.new(tex.outputs["Color"], nrm.inputs["Color"]) + nt.links.new(nrm.outputs["Normal"], bsdf.inputs["Normal"]) + + +def render_still(low, dirt, tex, path, engine): + scene = bpy.context.scene + wire_normal(dirt, tex) + for ob in list(scene.objects): + if ob.type == "MESH" and ob != low: + ob.hide_render = True + ob.hide_viewport = True + + low.rotation_euler.z = math.radians(-28.0) + low.rotation_euler.x = math.radians(0.0) + + floor_me = bpy.data.meshes.new("Floor") + bm = bmesh.new() + try: + bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0) + bm.to_mesh(floor_me) + finally: + bm.free() + fmat = bpy.data.materials.new("Floor") + fmat.use_nodes = True + fb = fmat.node_tree.nodes["Principled BSDF"] + fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0) + fb.inputs["Roughness"].default_value = 0.7 + floor_me.materials.append(fmat) + floor = bpy.data.objects.new("Floor", floor_me) + scene.collection.objects.link(floor) + wall = bpy.data.objects.new("Wall", floor_me.copy()) + wall.location = (0.0, 8.5, 0.0) + wall.rotation_euler = (math.radians(90), 0.0, 0.0) + scene.collection.objects.link(wall) + + world = bpy.data.worlds.new("World") + world.use_nodes = True + world.node_tree.nodes["Background"].inputs["Color"].default_value = ( + 0.02, 0.021, 0.025, 1.0, + ) + scene.world = world + + def light(name, loc, energy, size, col, rot): + ld = bpy.data.lights.new(name, "AREA") + ld.energy = energy + ld.size = size + ld.color = col + ob = bpy.data.objects.new(name, ld) + ob.location = loc + ob.rotation_euler = tuple(math.radians(a) for a in rot) + scene.collection.objects.link(ob) + + light("Key", (-3.6, -5.0, 5.8), 680.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36)) + light("Fill", (5.0, -3.6, 2.6), 48.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50)) + light("Wedge", (2.4, 4.2, 4.1), 640.0, 5.5, (1.0, 0.70, 0.40), (-70, 0, 198)) + + cam_data = bpy.data.cameras.new("Cam") + cam_data.lens = 50.0 + cam = bpy.data.objects.new("Cam", cam_data) + cam.location = (2.57, -3.51, 2.24) + scene.collection.objects.link(cam) + aim = bpy.data.objects.new("Aim", None) + aim.location = (0.0, 0.0, 0.24) + scene.collection.objects.link(aim) + con = cam.constraints.new("TRACK_TO") + con.target = aim + con.track_axis = "TRACK_NEGATIVE_Z" + con.up_axis = "UP_Y" + scene.camera = cam + + scene.render.engine = "CYCLES" if engine == "cycles" else eevee_engine_id() + if engine == "cycles": + scene.cycles.samples = 32 + scene.cycles.device = "CPU" + else: + try: + scene.eevee.taa_render_samples = 64 + except AttributeError: + pass + scene.render.resolution_x = 1280 + scene.render.resolution_y = 720 + scene.render.image_settings.file_format = ( + "WEBP" if path.lower().endswith(".webp") else "PNG" + ) + if path.lower().endswith(".webp"): + scene.render.image_settings.quality = 90 + scene.render.filepath = path + scene.view_settings.view_transform = "Standard" + + fcode = gallery_framing.check_framing( + scene, cam, hero=[low], elements=[low], stage=[floor, wall], + ) + if fcode: + return fcode + bpy.ops.render.render(write_still=True) + if not (os.path.exists(path) and os.path.getsize(path) > 0): + return fail("render produced no file", 14) + return 0 + + +def main(): + argv = sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else [] + p = argparse.ArgumentParser() + p.add_argument("--output", default=None) + p.add_argument("--engine", default="eevee", choices=("eevee", "cycles")) + p.add_argument( + "--skip-decimate", + action="store_true", + help="falsification: skip the LOD DECIMATE stage", + ) + args = p.parse_args(argv) + + code, low, _high, dirt, tex, _col = check(args.skip_decimate) + if code: + return code + if args.output: + rcode = render_still(low, dirt, tex, os.path.abspath(args.output), args.engine) + if rcode: + return rcode + print(f"rendered still {args.output}") + print("terrain-scatter OK") + return 0 + + +if __name__ == "__main__": + try: + sys.exit(main()) + except Exception as e: + traceback.print_exc() + print(f"FATAL: {e}", file=sys.stderr) + sys.exit(1) diff --git a/tests/smoke/catalog.json b/tests/smoke/catalog.json index d73ce53..4abc0ab 100644 --- a/tests/smoke/catalog.json +++ b/tests/smoke/catalog.json @@ -80,5 +80,7 @@ {"name": "campfire", "script": "showcase/campfire/campfire.py"}, {"name": "market-stall", "script": "showcase/market-stall/market_stall.py"}, {"name": "street-lantern", "script": "showcase/street-lantern/street_lantern.py"}, - {"name": "treasure-chest", "script": "showcase/treasure-chest/treasure_chest.py"} + {"name": "treasure-chest", "script": "showcase/treasure-chest/treasure_chest.py"}, + {"name": "terrain-scatter", "script": "showcase/terrain-scatter/terrain_scatter.py"}, + {"name": "fence-kit", "script": "showcase/fence-kit/fence_kit.py"} ]