diff --git a/.cursor-plugin/plugin.json b/.cursor-plugin/plugin.json index c60b645..0c76b83 100644 --- a/.cursor-plugin/plugin.json +++ b/.cursor-plugin/plugin.json @@ -146,6 +146,8 @@ "showcase/street-lantern", "showcase/treasure-chest", "showcase/terrain-scatter", - "showcase/fence-kit" + "showcase/fence-kit", + "showcase/watchtower", + "showcase/cart" ] } diff --git a/AGENTS.md b/AGENTS.md index 5fef89b..17d2def 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 9 showcase pieces (counts are CI-enforced against README.md +examples, and 11 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 89925b4..13c3df0 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, 9 pieces (sibling of examples/; see showcase/README.md) +showcase// - Budget-conformance props, 11 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 fa01acd..10fb0c6 100644 --- a/README.md +++ b/README.md @@ -18,7 +18,7 @@

- 16 skills  •  9 rules  •  3 templates  •  27 snippets  •  59 examples  •  9 showcase pieces + 16 skills  •  9 rules  •  3 templates  •  27 snippets  •  59 examples  •  11 showcase pieces

@@ -37,7 +37,7 @@ ## Overview -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. +This repository ships **16 skills, 9 rules, 3 templates, 27 snippets, 59 examples, and 11 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. @@ -84,6 +84,8 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show 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 +Watchtower: a timber lookout with X-braces, ladder, plank platform, and pyramidal roof on a dark studio floor +Cart: a two-wheel wooden cart with spoked wheels, slatted bed, and shafts 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. @@ -103,6 +105,10 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show [`fence-kit`](showcase/fence-kit/) — procedural post-and-rail fence section through the same pipeline. Falsifier `--skip-decimate` exits 9. +[`watchtower`](showcase/watchtower/) — procedural timber lookout with X-braces, ladder, platform, and pyramidal roof through the same pipeline. Falsifier `--skip-decimate` exits 9. + +[`cart`](showcase/cart/) — procedural two-wheel wooden cart with spoked wheels, slatted bed, and shafts 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 9c46be3..b76ced6 100644 --- a/ROADMAP.md +++ b/ROADMAP.md @@ -113,6 +113,8 @@ Not committed; target list for the next content version. (v0.3.0 shipped the smo - ~~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~~ **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 +- ~~Timber watchtower showcase~~ **SHIPPED** as `showcase/watchtower/` — corner posts, X-braces, plank platform, ladder, pyramidal roof; `--skip-decimate` exits 9 on the LOD1 ratio band +- ~~Two-wheel wooden cart showcase~~ **SHIPPED** as `showcase/cart/` — slatted bed, shafts, spoked wheels, iron hubs and axle; `--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)~~ **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 diff --git a/docs/gallery/assets/cart-hero.webp b/docs/gallery/assets/cart-hero.webp new file mode 100644 index 0000000..891b275 Binary files /dev/null and b/docs/gallery/assets/cart-hero.webp differ diff --git a/docs/gallery/assets/watchtower-hero.webp b/docs/gallery/assets/watchtower-hero.webp new file mode 100644 index 0000000..2361389 Binary files /dev/null and b/docs/gallery/assets/watchtower-hero.webp differ diff --git a/docs/gallery/cart/index.html b/docs/gallery/cart/index.html new file mode 100644 index 0000000..2441c4b --- /dev/null +++ b/docs/gallery/cart/index.html @@ -0,0 +1,1161 @@ + + + + + + cart — Examples — Blender Developer Tools + + + + + + + + + + + + + + + + + +

+ Examples Gallery +
+ GitHub +
+
+
+

cart

+

A procedural two-wheel wooden cart 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: 2572 tris, two materials with 100 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.547×0.749×0.656 m, LOD ratios in band, convex collider 306 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.
+
+ 
blender --background --python showcase/cart/cart.py --
+ +
+
+

A showcase piece, not an example. Procedural two-wheel wooden cart (slatted bed, side walls, shafts, spoked wheels, iron hubs and axle) 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 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 | 2470–2680 | 2572 / 2572 / 2572 | | LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | | LOD2 ratio | 0.10–0.35 of base | 0.2193 / 0.2193 / 0.2146 | | Materials | exactly 2 distinct, ≥24 metal faces | 2 slots, 100 metal | | UVs | in 0..1, AABB overlap ≤ 1e-5 | in range, overlap 0 | | Outer AABB | (1.547, 0.749, 0.656) m ± 0.01 | (1.5473, 0.7486, 0.6560), zmin 0 | | Collider tris | ≤ 360 | 306 | | Export | written, size > 0 | 202500 / 202500 / 202492 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. Export byte counts differ by 8 B on 5.2.1 (glTF serializer), not a gated axis.

+

--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 cart.py --
+blender --background --python cart.py -- --skip-decimate
+blender --background --python cart.py -- --output cart.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/cart/cart.py + View on GitHub → +
+ 
"""Game-ready two-wheel wooden cart — a showcase piece, not an example.
+
+Asserts budget conformance of a procedural cart (staved bed, side
+walls, shafts, spoked wheels, iron hubs and axle) 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. 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 cart.py --
+    blender --background --python cart.py -- --skip-decimate
+    blender --background --python cart.py -- --output cart.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
+
+RIM_MAJOR = 0.30
+RIM_MINOR = 0.028
+TRACK = 0.68
+AXLE_X = -0.16
+HUB_R = 0.052
+HUB_W = 0.046
+N_SPOKES = 8
+SPOKE_T = 0.018
+BED_L = 0.92
+BED_W = 0.50
+BED_T = 0.038
+WALL_H = 0.16
+WALL_T = 0.032
+SHAFT_L = 0.58
+SHAFT_T = 0.034
+N_SLATS = 6
+IRON_T = 0.014
+
+BBOX_TOL = 0.01
+OUTER_SIZE = (1.547, 0.749, 0.656)
+BASE_TRIS_MIN = 2470
+BASE_TRIS_MAX = 2680
+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 = 360
+BAKE_RES = 256
+CAGE_EXTRUSION = 0.08
+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_cyl(bm, loc, radius, 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=radius,
+        radius2=radius,
+        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 add_rim(bm, loc, major, minor, mat_idx, euler=(0.0, 0.0, 0.0)):
+    n_major = 16
+    n_minor = 8
+    rings = []
+    for i in range(n_major):
+        u = i * (2.0 * math.pi / n_major)
+        ring = []
+        for j in range(n_minor):
+            v = j * (2.0 * math.pi / n_minor)
+            x = (major + minor * math.cos(v)) * math.cos(u)
+            y = (major + minor * math.cos(v)) * math.sin(u)
+            z = minor * math.sin(v)
+            ring.append(bm.verts.new((x, y, z)))
+        rings.append(ring)
+    bm.verts.ensure_lookup_table()
+    for i in range(n_major):
+        i2 = (i + 1) % n_major
+        for j in range(n_minor):
+            j2 = (j + 1) % n_minor
+            face = bm.faces.new(
+                (rings[i][j], rings[i2][j], rings[i2][j2], rings[i][j2])
+            )
+            face.material_index = mat_idx
+    verts = [v for ring in rings for v in ring]
+    rot = Euler(euler).to_matrix()
+    origin = Vector(loc)
+    for v in verts:
+        v.co = rot @ v.co + origin
+    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 add_wheel(bm, loc, wood, metal):
+    wood.extend(
+        add_rim(bm, loc, RIM_MAJOR, RIM_MINOR, WOOD_IDX, euler=(math.pi / 2.0, 0.0, 0.0))
+    )
+    wood.extend(
+        add_cyl(
+            bm,
+            loc,
+            HUB_R,
+            HUB_W,
+            12,
+            WOOD_IDX,
+            euler=(math.pi / 2.0, 0.0, 0.0),
+        )
+    )
+    inner = HUB_R + 0.008
+    outer = RIM_MAJOR - RIM_MINOR * 0.55
+    mid_r = 0.5 * (inner + outer)
+    slen = outer - inner
+    for i in range(N_SPOKES):
+        a = i * (2.0 * math.pi / N_SPOKES)
+        dx = math.cos(a)
+        dz = math.sin(a)
+        cx = loc[0] + dx * mid_r
+        cy = loc[1]
+        cz = loc[2] + dz * mid_r
+        wood.extend(
+            add_box(
+                bm,
+                (cx, cy, cz),
+                (slen, SPOKE_T * 0.85, SPOKE_T),
+                WOOD_IDX,
+                euler=(0.0, -a, 0.0),
+            )
+        )
+    metal.extend(
+        add_cyl(
+            bm,
+            loc,
+            HUB_R + 0.010,
+            0.016,
+            12,
+            METAL_IDX,
+            euler=(math.pi / 2.0, 0.0, 0.0),
+        )
+    )
+    metal.extend(
+        add_cyl(
+            bm,
+            (loc[0], loc[1] + (HUB_W * 0.55 if loc[1] > 0 else -HUB_W * 0.55), loc[2]),
+            0.022,
+            0.018,
+            10,
+            METAL_IDX,
+            euler=(math.pi / 2.0, 0.0, 0.0),
+        )
+    )
+
+
+def build_cart_mesh(name, bevel_offset, bevel_segments):
+    bm = bmesh.new()
+    try:
+        body = []
+        wood_wheels = []
+        metal = []
+        axle_z = RIM_MAJOR
+        bed_z = axle_z + 0.10
+        bed_cx = 0.06
+
+        add_wheel(bm, (AXLE_X, TRACK / 2.0, axle_z), wood_wheels, metal)
+        add_wheel(bm, (AXLE_X, -TRACK / 2.0, axle_z), wood_wheels, metal)
+
+        metal.extend(
+            add_cyl(
+                bm,
+                (AXLE_X, 0.0, axle_z),
+                0.020,
+                TRACK + 0.06,
+                10,
+                METAL_IDX,
+                euler=(math.pi / 2.0, 0.0, 0.0),
+            )
+        )
+
+        slat_w = BED_W / N_SLATS
+        y0 = -BED_W / 2.0 + slat_w / 2.0
+        for i in range(N_SLATS):
+            y = y0 + i * slat_w
+            body.extend(
+                add_box(
+                    bm,
+                    (bed_cx, y, bed_z),
+                    (BED_L, slat_w * 0.88, BED_T),
+                    WOOD_IDX,
+                )
+            )
+        for ysign in (-1.0, 1.0):
+            body.extend(
+                add_box(
+                    bm,
+                    (bed_cx, ysign * (BED_W / 2.0 + WALL_T / 2.0), bed_z + WALL_H / 2.0),
+                    (BED_L * 0.98, WALL_T, WALL_H),
+                    WOOD_IDX,
+                )
+            )
+        body.extend(
+            add_box(
+                bm,
+                (bed_cx + BED_L / 2.0 - WALL_T / 2.0, 0.0, bed_z + WALL_H / 2.0 + 0.02),
+                (WALL_T, BED_W + WALL_T * 2.0, WALL_H + 0.04),
+                WOOD_IDX,
+            )
+        )
+        body.extend(
+            add_box(
+                bm,
+                (bed_cx - BED_L / 2.0 + WALL_T / 2.0, 0.0, bed_z + 0.06),
+                (WALL_T, BED_W + WALL_T, 0.12),
+                WOOD_IDX,
+            )
+        )
+        for xj in (bed_cx - BED_L * 0.32, bed_cx + BED_L * 0.28):
+            body.extend(
+                add_box(
+                    bm,
+                    (xj, 0.0, bed_z - BED_T / 2.0 - 0.022),
+                    (0.055, BED_W * 0.92, 0.044),
+                    WOOD_IDX,
+                )
+            )
+
+        shaft_x = bed_cx + BED_L / 2.0 + SHAFT_L / 2.0 - 0.04
+        shaft_z = bed_z - 0.02
+        pitch = math.radians(7.0)
+        for ysign in (-1.0, 1.0):
+            body.extend(
+                add_box(
+                    bm,
+                    (shaft_x, ysign * 0.12, shaft_z),
+                    (SHAFT_L, SHAFT_T, SHAFT_T),
+                    WOOD_IDX,
+                    euler=(0.0, pitch, 0.0),
+                )
+            )
+            metal.extend(
+                add_box(
+                    bm,
+                    (bed_cx + BED_L / 2.0 - 0.02, ysign * 0.12, bed_z - 0.01),
+                    (0.05, 0.042, IRON_T),
+                    METAL_IDX,
+                )
+            )
+
+        for sx, sy in (
+            (bed_cx - BED_L / 2.0 + 0.04, -BED_W / 2.0),
+            (bed_cx - BED_L / 2.0 + 0.04, BED_W / 2.0),
+            (bed_cx + BED_L / 2.0 - 0.04, -BED_W / 2.0),
+            (bed_cx + BED_L / 2.0 - 0.04, BED_W / 2.0),
+        ):
+            metal.extend(
+                add_box(
+                    bm,
+                    (sx, sy, bed_z + 0.01),
+                    (0.055, 0.055, IRON_T),
+                    METAL_IDX,
+                )
+            )
+
+        if bevel_offset > 0.0:
+            edges = list({e for v in body for e in v.link_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 = WOOD_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]
+        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, wood, metal):
+    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("CartNrm", 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_cart_mesh("CartLow", bevel_offset=0.005, bevel_segments=2)
+    high = build_cart_mesh("CartHigh", bevel_offset=0.005, bevel_segments=4)
+    wood = principled("CartWood", (0.42, 0.22, 0.08, 1.0), 0.0, 0.58)
+    metal = principled("CartIron", (0.13, 0.135, 0.15, 1.0), 1.0, 0.32)
+    assign_slots(low, wood, metal)
+    assign_slots(high, wood, metal)
+
+    if low.data is None or len(low.data.polygons) < 6:
+        return fail("cart 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("cart has no UV layer", 3), None, None, None, None, None
+    bake_result = bake_normal(high, low)
+
+    lod1 = make_lod(low, "CartLOD1", LOD1_TARGET, skip_decimate)
+    lod2 = make_lod(low, "CartLOD2", 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_cart_mesh("CartColSrc", bevel_offset=0.0, bevel_segments=1)
+    collider = convex_hull_collider(collider_src, "CartCollider")
+    bpy.data.objects.remove(collider_src, do_unlink=True)
+    col_tris = triangle_count(collider.data)
+
+    export_path = os.path.join(
+        tempfile.gettempdir(),
+        f"bdt_cart_{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(-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", (-3.4, -4.8, 5.4), 640.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36))
+    light("Fill", (4.8, -3.4, 2.4), 46.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50))
+    light("Wedge", (2.2, 4.0, 3.8), 600.0, 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 = (1.34, -1.62, 0.88)
+    scene.collection.objects.link(cam)
+    aim = bpy.data.objects.new("Aim", None)
+    aim.location = (0.05, 0.0, 0.30)
+    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("cart 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 63152c6..aec7c6a 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" /> - 60 examples + 62 examples
@@ -984,6 +984,28 @@

fence-kit

View example
+
+ + watchtower — A procedural timber watchtower through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract. + +
+

watchtower

+

A procedural timber watchtower through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.

+

witnesses Recomputed: 4656 tris, two materials with 60 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.910×0.927×1.822 m, LOD ratios in band, convex collider 64 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.

+ View example +
+
+
+ + cart — A procedural two-wheel wooden cart through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract. + +
+

cart

+

A procedural two-wheel wooden cart through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.

+

witnesses Recomputed: 2572 tris, two materials with 100 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.547×0.749×0.656 m, LOD ratios in band, convex collider 306 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.

+ View example +
+
diff --git a/docs/gallery/watchtower/index.html b/docs/gallery/watchtower/index.html new file mode 100644 index 0000000..bc3611f --- /dev/null +++ b/docs/gallery/watchtower/index.html @@ -0,0 +1,1129 @@ + + + + + + watchtower — Examples — Blender Developer Tools + + + + + + + + + + + + + + + + + +
+ Examples Gallery +
+ GitHub +
+
+
+

watchtower

+

A procedural timber watchtower 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: 4656 tris, two materials with 60 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.910×0.927×1.822 m, LOD ratios in band, convex collider 64 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.
+
+ 
blender --background --python showcase/watchtower/watchtower.py --
+ +
+
+

A showcase piece, not an example. Procedural timber lookout (corner posts, X-braces, plank platform, three-sided rail, ladder, pyramidal roof, iron shoes) 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 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 | 4550–4760 | 4656 / 4656 / 4656 | | LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | | LOD2 ratio | 0.10–0.35 of base | 0.2199 / 0.2199 / 0.2199 | | Materials | exactly 2 distinct, ≥24 metal faces | 2 slots, 60 metal | | UVs | in 0..1, AABB overlap ≤ 1e-5 | in range, overlap 0 | | Outer AABB | (0.910, 0.927, 1.822) m ± 0.01 | (0.9104, 0.9267, 1.8220), zmin 0 | | Collider tris | ≤ 96 | 64 | | Export | written, size > 0 | 334288 / 334288 / 334272 bytes |

+

DECIMATE COLLAPSE triangle counts are not required to match across series — the gate is a ratio band, not an exact count. This mesh's LOD2 ratio happened to match on all three binaries. Bake pixels are stochastic; the gate is has_data plus operator FINISHED, not byte-identity. Construction uses no RNG. Export byte counts differ by 16 B on 5.2.1 (glTF serializer), not a gated axis.

+

--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 watchtower.py --
+blender --background --python watchtower.py -- --skip-decimate
+blender --background --python watchtower.py -- --output tower.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/watchtower/watchtower.py + View on GitHub → +
+ 
"""Game-ready timber watchtower — a showcase piece, not an example.
+
+Asserts budget conformance of a procedural lookout (posts, braces,
+platform, ladder, pyramidal roof) 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. 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 watchtower.py --
+    blender --background --python watchtower.py -- --skip-decimate
+    blender --background --python watchtower.py -- --output tower.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
+
+HALF = 0.40
+POST = 0.080
+POST_H = 1.48
+PLAT_Z = 1.18
+RAIL_H = 0.36
+ROOF_H = 0.52
+BRACE_T = 0.038
+PLANK_T = 0.042
+IRON_T = 0.014
+SHOE_H = 0.032
+
+BBOX_TOL = 0.01
+OUTER_SIZE = (0.910, 0.927, 1.822)
+BASE_TRIS_MIN = 4550
+BASE_TRIS_MAX = 4760
+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 = 0.08
+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_tower_mesh(name, bevel_offset, bevel_segments):
+    bm = bmesh.new()
+    try:
+        wood = []
+        posts = (
+            (-HALF, -HALF),
+            (HALF, -HALF),
+            (-HALF, HALF),
+            (HALF, HALF),
+        )
+        for px, py in posts:
+            wood.extend(
+                add_box(bm, (px, py, POST_H / 2.0), (POST, POST, POST_H), WOOD_IDX)
+            )
+
+        span = 2.0 * HALF + POST * 0.15
+        for sign in (-1.0, 1.0):
+            wood.extend(
+                add_box(bm, (0.0, sign * HALF, 0.04), (span, POST * 0.92, 0.08), WOOD_IDX)
+            )
+            wood.extend(
+                add_box(bm, (sign * HALF, 0.0, 0.04), (POST * 0.92, span, 0.08), WOOD_IDX)
+            )
+            wood.extend(
+                add_box(
+                    bm,
+                    (0.0, sign * HALF, POST_H - 0.04),
+                    (span, POST * 0.85, 0.08),
+                    WOOD_IDX,
+                )
+            )
+            wood.extend(
+                add_box(
+                    bm,
+                    (sign * HALF, 0.0, POST_H - 0.04),
+                    (POST * 0.85, span, 0.08),
+                    WOOD_IDX,
+                )
+            )
+
+        rise = 0.72
+        run = 2.0 * HALF - POST
+        blen = math.hypot(run, rise)
+        bang = math.atan2(rise, run)
+        for ysign in (-1.0, 1.0):
+            for bang_sign in (-1.0, 1.0):
+                wood.extend(
+                    add_box(
+                        bm,
+                        (0.0, ysign * (HALF + POST * 0.15), 0.52),
+                        (blen, BRACE_T, BRACE_T),
+                        WOOD_IDX,
+                        euler=(0.0, bang_sign * bang, 0.0),
+                    )
+                )
+        for xsign in (-1.0, 1.0):
+            for bang_sign in (-1.0, 1.0):
+                wood.extend(
+                    add_box(
+                        bm,
+                        (xsign * (HALF + POST * 0.15), 0.0, 0.52),
+                        (BRACE_T, blen, BRACE_T),
+                        WOOD_IDX,
+                        euler=(bang_sign * bang, 0.0, 0.0),
+                    )
+                )
+
+        n_plank = 5
+        plank_w = (2.0 * HALF - 0.04) / n_plank
+        y0 = -HALF + 0.02 + plank_w / 2.0
+        for i in range(n_plank):
+            y = y0 + i * plank_w
+            wood.extend(
+                add_box(
+                    bm,
+                    (0.0, y, PLAT_Z + PLANK_T / 2.0),
+                    (2.0 * HALF + POST * 0.4, plank_w * 0.88, PLANK_T),
+                    WOOD_IDX,
+                )
+            )
+
+        rail_z = PLAT_Z + PLANK_T + RAIL_H * 0.55
+        for px, py in ((-HALF, HALF), (HALF, HALF), (HALF, -HALF), (-HALF, -HALF)):
+            wood.extend(
+                add_box(
+                    bm,
+                    (px, py, PLAT_Z + PLANK_T + RAIL_H / 2.0),
+                    (POST * 0.62, POST * 0.62, RAIL_H),
+                    WOOD_IDX,
+                )
+            )
+        wood.extend(
+            add_box(
+                bm,
+                (0.0, HALF, rail_z),
+                (2.0 * HALF, POST * 0.42, 0.045),
+                WOOD_IDX,
+            )
+        )
+        wood.extend(
+            add_box(
+                bm,
+                (HALF, 0.12, rail_z),
+                (POST * 0.42, 2.0 * HALF * 0.72, 0.045),
+                WOOD_IDX,
+            )
+        )
+        wood.extend(
+            add_box(
+                bm,
+                (-HALF, 0.12, rail_z),
+                (POST * 0.42, 2.0 * HALF * 0.72, 0.045),
+                WOOD_IDX,
+            )
+        )
+
+        stile_y = -HALF - POST * 0.55
+        for sx in (-0.13, 0.13):
+            wood.extend(
+                add_box(
+                    bm,
+                    (sx, stile_y, PLAT_Z / 2.0),
+                    (0.038, 0.042, PLAT_Z + 0.06),
+                    WOOD_IDX,
+                )
+            )
+        n_rung = 6
+        for i in range(n_rung):
+            z = 0.16 + i * (PLAT_Z - 0.22) / (n_rung - 1)
+            wood.extend(
+                add_box(bm, (0.0, stile_y, z), (0.28, 0.032, 0.032), WOOD_IDX)
+            )
+
+        wood.extend(
+            add_box(
+                bm,
+                (0.0, 0.0, PLAT_Z + PLANK_T + 0.03),
+                (2.0 * HALF + POST * 1.15, 2.0 * HALF + POST * 1.15, 0.05),
+                WOOD_IDX,
+            )
+        )
+        wood.extend(
+            add_cone(
+                bm,
+                (0.0, 0.0, PLAT_Z + PLANK_T + 0.05 + ROOF_H / 2.0),
+                HALF + POST * 0.95,
+                0.018,
+                ROOF_H,
+                4,
+                WOOD_IDX,
+                euler=(0.0, 0.0, math.pi / 4.0),
+            )
+        )
+
+        if bevel_offset > 0.0:
+            edges = list({e for v in wood for e in v.link_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 = WOOD_IDX
+
+        for px, py in posts:
+            add_box(
+                bm,
+                (px, py, SHOE_H / 2.0),
+                (POST * 1.38, POST * 1.38, SHOE_H),
+                METAL_IDX,
+            )
+            add_box(
+                bm,
+                (px, py, PLAT_Z + PLANK_T + IRON_T / 2.0),
+                (POST * 1.15, POST * 1.15, IRON_T),
+                METAL_IDX,
+            )
+        for sx in (-0.13, 0.13):
+            add_box(
+                bm,
+                (sx, stile_y, PLAT_Z + 0.02),
+                (0.05, 0.055, IRON_T),
+                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]
+        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, wood, metal):
+    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("TowerNrm", 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_tower_mesh("TowerLow", bevel_offset=0.006, bevel_segments=2)
+    high = build_tower_mesh("TowerHigh", bevel_offset=0.006, bevel_segments=4)
+    wood = principled("TowerWood", (0.44, 0.23, 0.08, 1.0), 0.0, 0.56)
+    metal = principled("TowerIron", (0.12, 0.125, 0.14, 1.0), 1.0, 0.30)
+    assign_slots(low, wood, metal)
+    assign_slots(high, wood, metal)
+
+    if low.data is None or len(low.data.polygons) < 6:
+        return fail("tower 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("tower has no UV layer", 3), None, None, None, None, None
+    bake_result = bake_normal(high, low)
+
+    lod1 = make_lod(low, "TowerLOD1", LOD1_TARGET, skip_decimate)
+    lod2 = make_lod(low, "TowerLOD2", 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_tower_mesh("TowerColSrc", bevel_offset=0.0, bevel_segments=1)
+    collider = convex_hull_collider(collider_src, "TowerCollider")
+    bpy.data.objects.remove(collider_src, do_unlink=True)
+    col_tris = triangle_count(collider.data)
+
+    export_path = os.path.join(
+        tempfile.gettempdir(),
+        f"bdt_watchtower_{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(-22.0)
+    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 = (3.85, -5.15, 2.55)
+    scene.collection.objects.link(cam)
+    aim = bpy.data.objects.new("Aim", None)
+    aim.location = (0.0, 0.0, 0.88)
+    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("watchtower 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/cart/README.md b/showcase/cart/README.md new file mode 100644 index 0000000..424a48a --- /dev/null +++ b/showcase/cart/README.md @@ -0,0 +1,74 @@ +# Cart + +A showcase piece, not an example. Procedural two-wheel wooden cart +(slatted bed, side walls, shafts, spoked wheels, iron hubs and axle) +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 `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 | 2470–2680 | 2572 / 2572 / 2572 | +| LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | +| LOD2 ratio | 0.10–0.35 of base | 0.2193 / 0.2193 / 0.2146 | +| Materials | exactly 2 distinct, ≥24 metal faces | 2 slots, 100 metal | +| UVs | in `0..1`, AABB overlap ≤ 1e-5 | in range, overlap 0 | +| Outer AABB | (1.547, 0.749, 0.656) m ± 0.01 | (1.5473, 0.7486, 0.6560), zmin 0 | +| Collider tris | ≤ 360 | 306 | +| Export | written, size > 0 | 202500 / 202500 / 202492 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. +Export byte counts differ by 8 B on 5.2.1 (glTF serializer), not a +gated axis. + +`--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 cart.py -- +blender --background --python cart.py -- --skip-decimate +blender --background --python cart.py -- --output cart.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/cart/cart.py b/showcase/cart/cart.py new file mode 100644 index 0000000..cb7f36e --- /dev/null +++ b/showcase/cart/cart.py @@ -0,0 +1,837 @@ +"""Game-ready two-wheel wooden cart — a showcase piece, not an example. + +Asserts budget conformance of a procedural cart (staved bed, side +walls, shafts, spoked wheels, iron hubs and axle) 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. 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 cart.py -- + blender --background --python cart.py -- --skip-decimate + blender --background --python cart.py -- --output cart.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 + +RIM_MAJOR = 0.30 +RIM_MINOR = 0.028 +TRACK = 0.68 +AXLE_X = -0.16 +HUB_R = 0.052 +HUB_W = 0.046 +N_SPOKES = 8 +SPOKE_T = 0.018 +BED_L = 0.92 +BED_W = 0.50 +BED_T = 0.038 +WALL_H = 0.16 +WALL_T = 0.032 +SHAFT_L = 0.58 +SHAFT_T = 0.034 +N_SLATS = 6 +IRON_T = 0.014 + +BBOX_TOL = 0.01 +OUTER_SIZE = (1.547, 0.749, 0.656) +BASE_TRIS_MIN = 2470 +BASE_TRIS_MAX = 2680 +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 = 360 +BAKE_RES = 256 +CAGE_EXTRUSION = 0.08 +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_cyl(bm, loc, radius, 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=radius, + radius2=radius, + 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 add_rim(bm, loc, major, minor, mat_idx, euler=(0.0, 0.0, 0.0)): + n_major = 16 + n_minor = 8 + rings = [] + for i in range(n_major): + u = i * (2.0 * math.pi / n_major) + ring = [] + for j in range(n_minor): + v = j * (2.0 * math.pi / n_minor) + x = (major + minor * math.cos(v)) * math.cos(u) + y = (major + minor * math.cos(v)) * math.sin(u) + z = minor * math.sin(v) + ring.append(bm.verts.new((x, y, z))) + rings.append(ring) + bm.verts.ensure_lookup_table() + for i in range(n_major): + i2 = (i + 1) % n_major + for j in range(n_minor): + j2 = (j + 1) % n_minor + face = bm.faces.new( + (rings[i][j], rings[i2][j], rings[i2][j2], rings[i][j2]) + ) + face.material_index = mat_idx + verts = [v for ring in rings for v in ring] + rot = Euler(euler).to_matrix() + origin = Vector(loc) + for v in verts: + v.co = rot @ v.co + origin + 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 add_wheel(bm, loc, wood, metal): + wood.extend( + add_rim(bm, loc, RIM_MAJOR, RIM_MINOR, WOOD_IDX, euler=(math.pi / 2.0, 0.0, 0.0)) + ) + wood.extend( + add_cyl( + bm, + loc, + HUB_R, + HUB_W, + 12, + WOOD_IDX, + euler=(math.pi / 2.0, 0.0, 0.0), + ) + ) + inner = HUB_R + 0.008 + outer = RIM_MAJOR - RIM_MINOR * 0.55 + mid_r = 0.5 * (inner + outer) + slen = outer - inner + for i in range(N_SPOKES): + a = i * (2.0 * math.pi / N_SPOKES) + dx = math.cos(a) + dz = math.sin(a) + cx = loc[0] + dx * mid_r + cy = loc[1] + cz = loc[2] + dz * mid_r + wood.extend( + add_box( + bm, + (cx, cy, cz), + (slen, SPOKE_T * 0.85, SPOKE_T), + WOOD_IDX, + euler=(0.0, -a, 0.0), + ) + ) + metal.extend( + add_cyl( + bm, + loc, + HUB_R + 0.010, + 0.016, + 12, + METAL_IDX, + euler=(math.pi / 2.0, 0.0, 0.0), + ) + ) + metal.extend( + add_cyl( + bm, + (loc[0], loc[1] + (HUB_W * 0.55 if loc[1] > 0 else -HUB_W * 0.55), loc[2]), + 0.022, + 0.018, + 10, + METAL_IDX, + euler=(math.pi / 2.0, 0.0, 0.0), + ) + ) + + +def build_cart_mesh(name, bevel_offset, bevel_segments): + bm = bmesh.new() + try: + body = [] + wood_wheels = [] + metal = [] + axle_z = RIM_MAJOR + bed_z = axle_z + 0.10 + bed_cx = 0.06 + + add_wheel(bm, (AXLE_X, TRACK / 2.0, axle_z), wood_wheels, metal) + add_wheel(bm, (AXLE_X, -TRACK / 2.0, axle_z), wood_wheels, metal) + + metal.extend( + add_cyl( + bm, + (AXLE_X, 0.0, axle_z), + 0.020, + TRACK + 0.06, + 10, + METAL_IDX, + euler=(math.pi / 2.0, 0.0, 0.0), + ) + ) + + slat_w = BED_W / N_SLATS + y0 = -BED_W / 2.0 + slat_w / 2.0 + for i in range(N_SLATS): + y = y0 + i * slat_w + body.extend( + add_box( + bm, + (bed_cx, y, bed_z), + (BED_L, slat_w * 0.88, BED_T), + WOOD_IDX, + ) + ) + for ysign in (-1.0, 1.0): + body.extend( + add_box( + bm, + (bed_cx, ysign * (BED_W / 2.0 + WALL_T / 2.0), bed_z + WALL_H / 2.0), + (BED_L * 0.98, WALL_T, WALL_H), + WOOD_IDX, + ) + ) + body.extend( + add_box( + bm, + (bed_cx + BED_L / 2.0 - WALL_T / 2.0, 0.0, bed_z + WALL_H / 2.0 + 0.02), + (WALL_T, BED_W + WALL_T * 2.0, WALL_H + 0.04), + WOOD_IDX, + ) + ) + body.extend( + add_box( + bm, + (bed_cx - BED_L / 2.0 + WALL_T / 2.0, 0.0, bed_z + 0.06), + (WALL_T, BED_W + WALL_T, 0.12), + WOOD_IDX, + ) + ) + for xj in (bed_cx - BED_L * 0.32, bed_cx + BED_L * 0.28): + body.extend( + add_box( + bm, + (xj, 0.0, bed_z - BED_T / 2.0 - 0.022), + (0.055, BED_W * 0.92, 0.044), + WOOD_IDX, + ) + ) + + shaft_x = bed_cx + BED_L / 2.0 + SHAFT_L / 2.0 - 0.04 + shaft_z = bed_z - 0.02 + pitch = math.radians(7.0) + for ysign in (-1.0, 1.0): + body.extend( + add_box( + bm, + (shaft_x, ysign * 0.12, shaft_z), + (SHAFT_L, SHAFT_T, SHAFT_T), + WOOD_IDX, + euler=(0.0, pitch, 0.0), + ) + ) + metal.extend( + add_box( + bm, + (bed_cx + BED_L / 2.0 - 0.02, ysign * 0.12, bed_z - 0.01), + (0.05, 0.042, IRON_T), + METAL_IDX, + ) + ) + + for sx, sy in ( + (bed_cx - BED_L / 2.0 + 0.04, -BED_W / 2.0), + (bed_cx - BED_L / 2.0 + 0.04, BED_W / 2.0), + (bed_cx + BED_L / 2.0 - 0.04, -BED_W / 2.0), + (bed_cx + BED_L / 2.0 - 0.04, BED_W / 2.0), + ): + metal.extend( + add_box( + bm, + (sx, sy, bed_z + 0.01), + (0.055, 0.055, IRON_T), + METAL_IDX, + ) + ) + + if bevel_offset > 0.0: + edges = list({e for v in body for e in v.link_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 = WOOD_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] + 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, wood, metal): + 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("CartNrm", 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_cart_mesh("CartLow", bevel_offset=0.005, bevel_segments=2) + high = build_cart_mesh("CartHigh", bevel_offset=0.005, bevel_segments=4) + wood = principled("CartWood", (0.42, 0.22, 0.08, 1.0), 0.0, 0.58) + metal = principled("CartIron", (0.13, 0.135, 0.15, 1.0), 1.0, 0.32) + assign_slots(low, wood, metal) + assign_slots(high, wood, metal) + + if low.data is None or len(low.data.polygons) < 6: + return fail("cart 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("cart has no UV layer", 3), None, None, None, None, None + bake_result = bake_normal(high, low) + + lod1 = make_lod(low, "CartLOD1", LOD1_TARGET, skip_decimate) + lod2 = make_lod(low, "CartLOD2", 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_cart_mesh("CartColSrc", bevel_offset=0.0, bevel_segments=1) + collider = convex_hull_collider(collider_src, "CartCollider") + bpy.data.objects.remove(collider_src, do_unlink=True) + col_tris = triangle_count(collider.data) + + export_path = os.path.join( + tempfile.gettempdir(), + f"bdt_cart_{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(-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", (-3.4, -4.8, 5.4), 640.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36)) + light("Fill", (4.8, -3.4, 2.4), 46.0, 8.0, (0.72, 0.82, 1.0), (62, 0, 50)) + light("Wedge", (2.2, 4.0, 3.8), 600.0, 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 = (1.34, -1.62, 0.88) + scene.collection.objects.link(cam) + aim = bpy.data.objects.new("Aim", None) + aim.location = (0.05, 0.0, 0.30) + 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("cart 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/cart/preview.webp b/showcase/cart/preview.webp new file mode 100644 index 0000000..c7127ce Binary files /dev/null and b/showcase/cart/preview.webp differ diff --git a/showcase/gallery.json b/showcase/gallery.json index 5eb3818..87b5241 100644 --- a/showcase/gallery.json +++ b/showcase/gallery.json @@ -112,6 +112,30 @@ "mesh", "export" ] + }, + { + "name": "watchtower", + "dir": "showcase/watchtower", + "teaches": "A procedural timber watchtower through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.", + "witnessesFix": "Recomputed: 4656 tris, two materials with 60 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.910×0.927×1.822 m, LOD ratios in band, convex collider 64 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.", + "hero": "docs/gallery/assets/watchtower-hero.webp", + "preview": "showcase/watchtower/preview.webp", + "tags": [ + "mesh", + "export" + ] + }, + { + "name": "cart", + "dir": "showcase/cart", + "teaches": "A procedural two-wheel wooden cart through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.", + "witnessesFix": "Recomputed: 2572 tris, two materials with 100 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 1.547×0.749×0.656 m, LOD ratios in band, convex collider 306 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.", + "hero": "docs/gallery/assets/cart-hero.webp", + "preview": "showcase/cart/preview.webp", + "tags": [ + "mesh", + "export" + ] } ] } diff --git a/showcase/watchtower/README.md b/showcase/watchtower/README.md new file mode 100644 index 0000000..d11249a --- /dev/null +++ b/showcase/watchtower/README.md @@ -0,0 +1,74 @@ +# Watchtower + +A showcase piece, not an example. Procedural timber lookout (corner +posts, X-braces, plank platform, three-sided rail, ladder, pyramidal +roof, iron shoes) 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 `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 | 4550–4760 | 4656 / 4656 / 4656 | +| LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | +| LOD2 ratio | 0.10–0.35 of base | 0.2199 / 0.2199 / 0.2199 | +| Materials | exactly 2 distinct, ≥24 metal faces | 2 slots, 60 metal | +| UVs | in `0..1`, AABB overlap ≤ 1e-5 | in range, overlap 0 | +| Outer AABB | (0.910, 0.927, 1.822) m ± 0.01 | (0.9104, 0.9267, 1.8220), zmin 0 | +| Collider tris | ≤ 96 | 64 | +| Export | written, size > 0 | 334288 / 334288 / 334272 bytes | + +DECIMATE COLLAPSE triangle counts are **not** required to match across +series — the gate is a ratio band, not an exact count. This mesh's LOD2 +ratio happened to match on all three binaries. Bake pixels are +stochastic; the gate is `has_data` plus operator `FINISHED`, not +byte-identity. Construction uses no RNG. Export byte counts differ by +16 B on 5.2.1 (glTF serializer), not a gated axis. + +`--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 watchtower.py -- +blender --background --python watchtower.py -- --skip-decimate +blender --background --python watchtower.py -- --output tower.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/watchtower/preview.webp b/showcase/watchtower/preview.webp new file mode 100644 index 0000000..a268a34 Binary files /dev/null and b/showcase/watchtower/preview.webp differ diff --git a/showcase/watchtower/watchtower.py b/showcase/watchtower/watchtower.py new file mode 100644 index 0000000..576fbfa --- /dev/null +++ b/showcase/watchtower/watchtower.py @@ -0,0 +1,805 @@ +"""Game-ready timber watchtower — a showcase piece, not an example. + +Asserts budget conformance of a procedural lookout (posts, braces, +platform, ladder, pyramidal roof) 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. 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 watchtower.py -- + blender --background --python watchtower.py -- --skip-decimate + blender --background --python watchtower.py -- --output tower.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 + +HALF = 0.40 +POST = 0.080 +POST_H = 1.48 +PLAT_Z = 1.18 +RAIL_H = 0.36 +ROOF_H = 0.52 +BRACE_T = 0.038 +PLANK_T = 0.042 +IRON_T = 0.014 +SHOE_H = 0.032 + +BBOX_TOL = 0.01 +OUTER_SIZE = (0.910, 0.927, 1.822) +BASE_TRIS_MIN = 4550 +BASE_TRIS_MAX = 4760 +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 = 0.08 +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_tower_mesh(name, bevel_offset, bevel_segments): + bm = bmesh.new() + try: + wood = [] + posts = ( + (-HALF, -HALF), + (HALF, -HALF), + (-HALF, HALF), + (HALF, HALF), + ) + for px, py in posts: + wood.extend( + add_box(bm, (px, py, POST_H / 2.0), (POST, POST, POST_H), WOOD_IDX) + ) + + span = 2.0 * HALF + POST * 0.15 + for sign in (-1.0, 1.0): + wood.extend( + add_box(bm, (0.0, sign * HALF, 0.04), (span, POST * 0.92, 0.08), WOOD_IDX) + ) + wood.extend( + add_box(bm, (sign * HALF, 0.0, 0.04), (POST * 0.92, span, 0.08), WOOD_IDX) + ) + wood.extend( + add_box( + bm, + (0.0, sign * HALF, POST_H - 0.04), + (span, POST * 0.85, 0.08), + WOOD_IDX, + ) + ) + wood.extend( + add_box( + bm, + (sign * HALF, 0.0, POST_H - 0.04), + (POST * 0.85, span, 0.08), + WOOD_IDX, + ) + ) + + rise = 0.72 + run = 2.0 * HALF - POST + blen = math.hypot(run, rise) + bang = math.atan2(rise, run) + for ysign in (-1.0, 1.0): + for bang_sign in (-1.0, 1.0): + wood.extend( + add_box( + bm, + (0.0, ysign * (HALF + POST * 0.15), 0.52), + (blen, BRACE_T, BRACE_T), + WOOD_IDX, + euler=(0.0, bang_sign * bang, 0.0), + ) + ) + for xsign in (-1.0, 1.0): + for bang_sign in (-1.0, 1.0): + wood.extend( + add_box( + bm, + (xsign * (HALF + POST * 0.15), 0.0, 0.52), + (BRACE_T, blen, BRACE_T), + WOOD_IDX, + euler=(bang_sign * bang, 0.0, 0.0), + ) + ) + + n_plank = 5 + plank_w = (2.0 * HALF - 0.04) / n_plank + y0 = -HALF + 0.02 + plank_w / 2.0 + for i in range(n_plank): + y = y0 + i * plank_w + wood.extend( + add_box( + bm, + (0.0, y, PLAT_Z + PLANK_T / 2.0), + (2.0 * HALF + POST * 0.4, plank_w * 0.88, PLANK_T), + WOOD_IDX, + ) + ) + + rail_z = PLAT_Z + PLANK_T + RAIL_H * 0.55 + for px, py in ((-HALF, HALF), (HALF, HALF), (HALF, -HALF), (-HALF, -HALF)): + wood.extend( + add_box( + bm, + (px, py, PLAT_Z + PLANK_T + RAIL_H / 2.0), + (POST * 0.62, POST * 0.62, RAIL_H), + WOOD_IDX, + ) + ) + wood.extend( + add_box( + bm, + (0.0, HALF, rail_z), + (2.0 * HALF, POST * 0.42, 0.045), + WOOD_IDX, + ) + ) + wood.extend( + add_box( + bm, + (HALF, 0.12, rail_z), + (POST * 0.42, 2.0 * HALF * 0.72, 0.045), + WOOD_IDX, + ) + ) + wood.extend( + add_box( + bm, + (-HALF, 0.12, rail_z), + (POST * 0.42, 2.0 * HALF * 0.72, 0.045), + WOOD_IDX, + ) + ) + + stile_y = -HALF - POST * 0.55 + for sx in (-0.13, 0.13): + wood.extend( + add_box( + bm, + (sx, stile_y, PLAT_Z / 2.0), + (0.038, 0.042, PLAT_Z + 0.06), + WOOD_IDX, + ) + ) + n_rung = 6 + for i in range(n_rung): + z = 0.16 + i * (PLAT_Z - 0.22) / (n_rung - 1) + wood.extend( + add_box(bm, (0.0, stile_y, z), (0.28, 0.032, 0.032), WOOD_IDX) + ) + + wood.extend( + add_box( + bm, + (0.0, 0.0, PLAT_Z + PLANK_T + 0.03), + (2.0 * HALF + POST * 1.15, 2.0 * HALF + POST * 1.15, 0.05), + WOOD_IDX, + ) + ) + wood.extend( + add_cone( + bm, + (0.0, 0.0, PLAT_Z + PLANK_T + 0.05 + ROOF_H / 2.0), + HALF + POST * 0.95, + 0.018, + ROOF_H, + 4, + WOOD_IDX, + euler=(0.0, 0.0, math.pi / 4.0), + ) + ) + + if bevel_offset > 0.0: + edges = list({e for v in wood for e in v.link_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 = WOOD_IDX + + for px, py in posts: + add_box( + bm, + (px, py, SHOE_H / 2.0), + (POST * 1.38, POST * 1.38, SHOE_H), + METAL_IDX, + ) + add_box( + bm, + (px, py, PLAT_Z + PLANK_T + IRON_T / 2.0), + (POST * 1.15, POST * 1.15, IRON_T), + METAL_IDX, + ) + for sx in (-0.13, 0.13): + add_box( + bm, + (sx, stile_y, PLAT_Z + 0.02), + (0.05, 0.055, IRON_T), + 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] + 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, wood, metal): + 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("TowerNrm", 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_tower_mesh("TowerLow", bevel_offset=0.006, bevel_segments=2) + high = build_tower_mesh("TowerHigh", bevel_offset=0.006, bevel_segments=4) + wood = principled("TowerWood", (0.44, 0.23, 0.08, 1.0), 0.0, 0.56) + metal = principled("TowerIron", (0.12, 0.125, 0.14, 1.0), 1.0, 0.30) + assign_slots(low, wood, metal) + assign_slots(high, wood, metal) + + if low.data is None or len(low.data.polygons) < 6: + return fail("tower 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("tower has no UV layer", 3), None, None, None, None, None + bake_result = bake_normal(high, low) + + lod1 = make_lod(low, "TowerLOD1", LOD1_TARGET, skip_decimate) + lod2 = make_lod(low, "TowerLOD2", 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_tower_mesh("TowerColSrc", bevel_offset=0.0, bevel_segments=1) + collider = convex_hull_collider(collider_src, "TowerCollider") + bpy.data.objects.remove(collider_src, do_unlink=True) + col_tris = triangle_count(collider.data) + + export_path = os.path.join( + tempfile.gettempdir(), + f"bdt_watchtower_{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(-22.0) + 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 = (3.85, -5.15, 2.55) + scene.collection.objects.link(cam) + aim = bpy.data.objects.new("Aim", None) + aim.location = (0.0, 0.0, 0.88) + 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("watchtower 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 4abc0ab..30a08cf 100644 --- a/tests/smoke/catalog.json +++ b/tests/smoke/catalog.json @@ -82,5 +82,7 @@ {"name": "street-lantern", "script": "showcase/street-lantern/street_lantern.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"} + {"name": "fence-kit", "script": "showcase/fence-kit/fence_kit.py"}, + {"name": "watchtower", "script": "showcase/watchtower/watchtower.py"}, + {"name": "cart", "script": "showcase/cart/cart.py"} ]