diff --git a/.cursor-plugin/plugin.json b/.cursor-plugin/plugin.json index c45afbe..090f795 100644 --- a/.cursor-plugin/plugin.json +++ b/.cursor-plugin/plugin.json @@ -152,6 +152,8 @@ "showcase/park-bench", "showcase/wheelbarrow", "showcase/anvil", - "showcase/water-trough" + "showcase/water-trough", + "showcase/hitching-post", + "showcase/grindstone" ] } diff --git a/AGENTS.md b/AGENTS.md index 6ce0c0e..883678e 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 15 showcase pieces (counts are CI-enforced against README.md) +examples, and 17 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 752008f..759fb8a 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, 15 pieces (sibling of examples/; see showcase/README.md) +showcase// - Budget-conformance props, 17 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 fdceebd..64d63ed 100644 --- a/README.md +++ b/README.md @@ -18,7 +18,7 @@

- 16 skills  •  9 rules  •  3 templates  •  27 snippets  •  59 examples  •  15 showcase pieces + 16 skills  •  9 rules  •  3 templates  •  27 snippets  •  59 examples  •  17 showcase pieces

@@ -37,7 +37,7 @@ ## Overview -This repository ships **16 skills, 9 rules, 3 templates, 27 snippets, 59 examples, and 15 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 17 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. @@ -90,6 +90,8 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show Wheelbarrow: a staved wooden tray with iron straps, a spoked wheel, rear legs, and handles on a dark studio floor Anvil: a London-pattern anvil on a hooped timber stump on a dark studio floor Water trough: a staved wooden trough on trestle legs with iron straps on a dark studio floor +Hitching post: a square timber post with a pyramidal cap, cross-arm, iron bands, and two hitching rings on a dark studio floor +Grindstone: a stone wheel on a timber A-frame with an iron axle, hubs, crank, and tray 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. @@ -121,6 +123,10 @@ Budget-conformance props. Not examples. Conventions: [`showcase/README.md`](show [`water-trough`](showcase/water-trough/) — procedural staved water trough on a timber stand through the same pipeline. Falsifier `--skip-decimate` exits 9. +[`hitching-post`](showcase/hitching-post/) — procedural timber hitching post with a cross-arm and iron rings through the same pipeline. Falsifier `--skip-decimate` exits 9. + +[`grindstone`](showcase/grindstone/) — procedural grindstone on a timber trestle with iron axle and crank 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 c57cd3c..ef8207a 100644 --- a/ROADMAP.md +++ b/ROADMAP.md @@ -119,8 +119,10 @@ Not committed; target list for the next content version. (v0.3.0 shipped the smo - ~~Wooden wheelbarrow (staved tray, single wheel, handles) as a game-prop showcase piece~~ **SHIPPED** as `showcase/wheelbarrow/` — staved U-tray, iron straps, spoked wheel, rear legs; `--skip-decimate` exits 9 on the LOD1 ratio band - ~~Blacksmith anvil on a timber stump as a game-prop showcase piece~~ **SHIPPED** as `showcase/anvil/` — London-pattern horn, face, heel, waist, hooped stump; `--skip-decimate` exits 9 on the LOD1 ratio band - ~~Staved wooden water trough on a stand as a game-prop showcase piece~~ **SHIPPED** as `showcase/water-trough/` — U-staves, end boards, iron straps, trestle legs; `--skip-decimate` exits 9 on the LOD1 ratio band -- Hitching post with iron ring as a game-prop showcase piece -- Grindstone on a timber trestle as a game-prop showcase piece +- ~~Hitching post with iron ring as a game-prop showcase piece~~ **SHIPPED** as `showcase/hitching-post/` — square post, pyramidal cap, cross-arm, iron shoe, bands, two rings; `--skip-decimate` exits 9 on the LOD1 ratio band +- ~~Grindstone on a timber trestle as a game-prop showcase piece~~ **SHIPPED** as `showcase/grindstone/` — stone wheel, A-frame trestle, iron axle, hubs, crank; `--skip-decimate` exits 9 on the LOD1 ratio band +- Cast-iron village hand pump as a game-prop showcase piece +- Timber fingerboard signpost 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 - ~~Custom ID-property delete witness~~ **SHIPPED** as `examples/cross-version-property-delete/` — IDs built via `bpy.data.objects.new` (not `active_object`); `property_unset` is TypeError and leaves the key; `del` removes it on 4.5 LTS and 5.x diff --git a/docs/gallery/assets/grindstone-hero.webp b/docs/gallery/assets/grindstone-hero.webp new file mode 100644 index 0000000..ed1ef06 Binary files /dev/null and b/docs/gallery/assets/grindstone-hero.webp differ diff --git a/docs/gallery/assets/hitching-post-hero.webp b/docs/gallery/assets/hitching-post-hero.webp new file mode 100644 index 0000000..2c65ebe Binary files /dev/null and b/docs/gallery/assets/hitching-post-hero.webp differ diff --git a/docs/gallery/grindstone/index.html b/docs/gallery/grindstone/index.html new file mode 100644 index 0000000..3590e62 --- /dev/null +++ b/docs/gallery/grindstone/index.html @@ -0,0 +1,1152 @@ + + + + + + grindstone — Examples — Blender Developer Tools + + + + + + + + + + + + + + + + + +

+ Examples Gallery +
+ GitHub +
+
+
+

grindstone

+

A procedural grindstone on a timber trestle 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: 1604 tris, three materials with 80 metal and 26 stone faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.630×0.615×0.575 m, LOD ratios in band, convex collider 130 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.
+
+ 
blender --background --python showcase/grindstone/grindstone.py --
+ +
+
+

A showcase piece, not an example. Procedural grindstone (stone wheel, timber A-frame trestle, iron axle, hubs, crank, and tray) 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 | 1480–1720 | 1604 / 1604 / 1604 | | LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | | LOD2 ratio | 0.10–0.35 of base | 0.2195 / 0.2195 / 0.2195 | | Materials | exactly 3 distinct, ≥24 metal and stone faces | 3 slots, 80 metal, 26 stone | | UVs | in 0..1, AABB overlap ≤ 1e-5 | in range, overlap 0 | | Outer AABB | (0.630, 0.615, 0.575) m ± 0.01 | (0.6300, 0.6150, 0.5750), zmin 0 | | Collider tris | ≤ 180 | 130 | | Export | written, size > 0 | 123436 / 123436 / 123416 bytes |

+

DECIMATE COLLAPSE triangle counts are not identical across series — 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 20 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 grindstone.py --
+blender --background --python grindstone.py -- --skip-decimate
+blender --background --python grindstone.py -- --output grindstone.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 ≠ 3 distinct slots, or wood/stone/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/grindstone/grindstone.py + View on GitHub → +
+ 
"""Game-ready grindstone — a showcase piece, not an example.
+
+Asserts budget conformance of a procedural grindstone (stone wheel,
+timber trestle, iron axle, hubs, and crank) after composing shipped
+pipeline pieces: bmesh construction, UVs, three 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 grindstone.py --
+    blender --background --python grindstone.py -- --skip-decimate
+    blender --background --python grindstone.py -- --output grindstone.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
+
+STONE_R = 0.235
+STONE_T = 0.058
+STONE_SEGS = 24
+AXLE_Z = 0.34
+FRAME_Y = 0.175
+LEG_SPREAD = 0.28
+LEG_XY = (0.044, 0.044)
+AXLE_R = 0.016
+AXLE_LEN = 0.50
+HUB_R = 0.040
+HUB_T = 0.026
+TRAY_L = 0.46
+TRAY_W = 0.26
+TRAY_H = 0.055
+CRANK_ARM = 0.14
+HANDLE_L = 0.10
+
+BBOX_TOL = 0.01
+OUTER_SIZE = (0.630, 0.615, 0.575)
+BASE_TRIS_MIN = 1480
+BASE_TRIS_MAX = 1720
+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 = 3
+UV_EPS = 1e-4
+UV_OVERLAP_MAX = 1e-5
+COLLIDER_TRIS_MAX = 180
+BAKE_RES = 256
+CAGE_EXTRUSION = 0.08
+METAL_FACES_MIN = 24
+WOOD_FACES_MIN = 12
+STONE_FACES_MIN = 24
+
+WOOD_IDX = 0
+STONE_IDX = 1
+METAL_IDX = 2
+
+
+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_oriented_box(bm, a, b, scale_xy, mat_idx):
+    a = Vector(a)
+    b = Vector(b)
+    delta = b - a
+    length = delta.length
+    if length < 1e-8:
+        return []
+    quat = Vector((0.0, 0.0, 1.0)).rotation_difference(delta.normalized())
+    eul = quat.to_euler("XYZ")
+    return add_box(
+        bm,
+        ((a + b) * 0.5),
+        (scale_xy[0], scale_xy[1], length),
+        mat_idx,
+        euler=(eul.x, eul.y, eul.z),
+    )
+
+
+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_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_grindstone_mesh(name, bevel_offset, bevel_segments):
+    bm = bmesh.new()
+    try:
+        wood = []
+        stone = []
+        metal = []
+
+        for y in (-FRAME_Y, FRAME_Y):
+            wood.extend(
+                add_oriented_box(
+                    bm,
+                    (-LEG_SPREAD, y, 0.022),
+                    (0.0, y, AXLE_Z),
+                    LEG_XY,
+                    WOOD_IDX,
+                )
+            )
+            wood.extend(
+                add_oriented_box(
+                    bm,
+                    (LEG_SPREAD, y, 0.022),
+                    (0.0, y, AXLE_Z),
+                    LEG_XY,
+                    WOOD_IDX,
+                )
+            )
+            wood.extend(
+                add_box(
+                    bm,
+                    (0.0, y, 0.072),
+                    (LEG_SPREAD * 1.55, 0.038, 0.038),
+                    WOOD_IDX,
+                )
+            )
+            wood.extend(
+                add_box(
+                    bm,
+                    (0.0, y, AXLE_Z),
+                    (0.090, 0.070, 0.070),
+                    WOOD_IDX,
+                )
+            )
+
+        wood.extend(
+            add_box(
+                bm,
+                (0.0, 0.0, 0.078),
+                (0.070, FRAME_Y * 2.0 + 0.04, 0.040),
+                WOOD_IDX,
+            )
+        )
+        wood.extend(
+            add_box(
+                bm,
+                (0.0, 0.0, TRAY_H / 2.0 + 0.004),
+                (TRAY_L, TRAY_W, TRAY_H),
+                WOOD_IDX,
+            )
+        )
+        wood.extend(
+            add_cyl(
+                bm,
+                (0.0, FRAME_Y + AXLE_LEN * 0.28, AXLE_Z + CRANK_ARM),
+                0.014,
+                HANDLE_L,
+                8,
+                WOOD_IDX,
+                euler=(math.pi / 2.0, 0.0, 0.0),
+            )
+        )
+
+        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
+
+        stone.extend(
+            add_cyl(
+                bm,
+                (0.0, 0.0, AXLE_Z),
+                STONE_R,
+                STONE_T,
+                STONE_SEGS,
+                STONE_IDX,
+                euler=(math.pi / 2.0, 0.0, 0.0),
+            )
+        )
+
+        metal.extend(
+            add_cyl(
+                bm,
+                (0.0, 0.0, AXLE_Z),
+                AXLE_R,
+                AXLE_LEN,
+                10,
+                METAL_IDX,
+                euler=(math.pi / 2.0, 0.0, 0.0),
+            )
+        )
+        for y in (-STONE_T / 2.0 - HUB_T / 2.0 + 0.004, STONE_T / 2.0 + HUB_T / 2.0 - 0.004):
+            metal.extend(
+                add_cyl(
+                    bm,
+                    (0.0, y, AXLE_Z),
+                    HUB_R,
+                    HUB_T,
+                    12,
+                    METAL_IDX,
+                    euler=(math.pi / 2.0, 0.0, 0.0),
+                )
+            )
+        crank_y = FRAME_Y + AXLE_LEN * 0.22
+        metal.extend(
+            add_box(
+                bm,
+                (0.0, crank_y, AXLE_Z + CRANK_ARM / 2.0),
+                (0.018, 0.018, CRANK_ARM + 0.02),
+                METAL_IDX,
+            )
+        )
+        metal.extend(
+            add_cyl(
+                bm,
+                (0.0, crank_y, AXLE_Z + CRANK_ARM),
+                0.010,
+                HANDLE_L * 0.55,
+                8,
+                METAL_IDX,
+                euler=(math.pi / 2.0, 0.0, 0.0),
+            )
+        )
+        for y in (-FRAME_Y, FRAME_Y):
+            for x in (-LEG_SPREAD, LEG_SPREAD):
+                metal.extend(
+                    add_box(
+                        bm,
+                        (x, y, 0.018),
+                        (0.070, 0.070, 0.036),
+                        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]
+        rcx = 0.5 * (min(xs) + max(xs))
+        rcy = 0.5 * (min(ys) + max(ys))
+        zmin = min(zs)
+        for v in bm.verts:
+            v.co.x -= rcx
+            v.co.y -= rcy
+            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, stone, metal):
+    mats = obj.data.materials
+    wanted = (wood, stone, 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("GrindstoneNrm", 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 = STONE_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_grindstone_mesh("GrindstoneLow", bevel_offset=0.004, bevel_segments=2)
+    high = build_grindstone_mesh("GrindstoneHigh", bevel_offset=0.004, bevel_segments=4)
+    wood = principled("GrindstoneWood", (0.36, 0.19, 0.07, 1.0), 0.0, 0.60)
+    stone = principled("GrindstoneStone", (0.46, 0.44, 0.41, 1.0), 0.0, 0.86)
+    metal = principled("GrindstoneIron", (0.14, 0.145, 0.155, 1.0), 1.0, 0.38)
+    assign_slots(low, wood, stone, metal)
+    assign_slots(high, wood, stone, metal)
+
+    if low.data is None or len(low.data.polygons) < 6:
+        return fail("grindstone 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, stone)
+    if img is None:
+        return fail("grindstone has no UV layer", 3), None, None, None, None, None
+    bake_result = bake_normal(high, low)
+
+    lod1 = make_lod(low, "GrindstoneLOD1", LOD1_TARGET, skip_decimate)
+    lod2 = make_lod(low, "GrindstoneLOD2", 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_grindstone_mesh(
+        "GrindstoneColSrc", bevel_offset=0.0, bevel_segments=1
+    )
+    collider = convex_hull_collider(collider_src, "GrindstoneCollider")
+    bpy.data.objects.remove(collider_src, do_unlink=True)
+    col_tris = triangle_count(collider.data)
+
+    export_path = os.path.join(
+        tempfile.gettempdir(),
+        f"bdt_grindstone_{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 idx_counts.get(STONE_IDX, 0) < STONE_FACES_MIN:
+        return fail(
+            f"stone faces {idx_counts.get(STONE_IDX, 0)} < {STONE_FACES_MIN}",
+            5,
+        ), None, None, None, None, None
+    if idx_counts.get(WOOD_IDX, 0) < WOOD_FACES_MIN:
+        return fail(
+            f"wood faces {idx_counts.get(WOOD_IDX, 0)} < {WOOD_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, stone, tex, collider
+
+
+def wire_normal(mat, tex):
+    nt = mat.node_tree
+    bsdf = nt.nodes["Principled BSDF"]
+    nrm = nt.nodes.new("ShaderNodeNormalMap")
+    nrm.inputs["Strength"].default_value = 1.0
+    nt.links.new(tex.outputs["Color"], nrm.inputs["Color"])
+    nt.links.new(nrm.outputs["Normal"], bsdf.inputs["Normal"])
+
+
+def render_still(low, wood, tex, path, engine):
+    scene = bpy.context.scene
+    wire_normal(wood, tex)
+    for ob in list(scene.objects):
+        if ob.type == "MESH" and ob != low:
+            ob.hide_render = True
+            ob.hide_viewport = True
+
+    low.rotation_euler.z = math.radians(-16.0)
+    low.rotation_euler.x = math.radians(0.0)
+
+    floor_me = bpy.data.meshes.new("Floor")
+    bm = bmesh.new()
+    try:
+        bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0)
+        bm.to_mesh(floor_me)
+    finally:
+        bm.free()
+    fmat = bpy.data.materials.new("Floor")
+    fmat.use_nodes = True
+    fb = fmat.node_tree.nodes["Principled BSDF"]
+    fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0)
+    fb.inputs["Roughness"].default_value = 0.7
+    floor_me.materials.append(fmat)
+    floor = bpy.data.objects.new("Floor", floor_me)
+    scene.collection.objects.link(floor)
+    wall = bpy.data.objects.new("Wall", floor_me.copy())
+    wall.location = (0.0, 8.5, 0.0)
+    wall.rotation_euler = (math.radians(90), 0.0, 0.0)
+    scene.collection.objects.link(wall)
+
+    world = bpy.data.worlds.new("World")
+    world.use_nodes = True
+    world.node_tree.nodes["Background"].inputs["Color"].default_value = (
+        0.02, 0.021, 0.025, 1.0,
+    )
+    scene.world = world
+
+    def light(name, loc, energy, size, col, rot):
+        ld = bpy.data.lights.new(name, "AREA")
+        ld.energy = energy
+        ld.size = size
+        ld.color = col
+        ob = bpy.data.objects.new(name, ld)
+        ob.location = loc
+        ob.rotation_euler = tuple(math.radians(a) for a in rot)
+        scene.collection.objects.link(ob)
+
+    light("Key", (-3.6, -5.0, 5.4), 660.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36))
+    light("Fill", (5.0, -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 = (1.48, -1.82, 0.86)
+    scene.collection.objects.link(cam)
+    aim = bpy.data.objects.new("Aim", None)
+    aim.location = (0.0, 0.0, 0.28)
+    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, hero_mat, tex, _col = check(args.skip_decimate)
+    if code:
+        return code
+    if args.output:
+        rcode = render_still(low, hero_mat, tex, os.path.abspath(args.output), args.engine)
+        if rcode:
+            return rcode
+        print(f"rendered still {args.output}")
+    print("grindstone 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/hitching-post/index.html b/docs/gallery/hitching-post/index.html new file mode 100644 index 0000000..701d65f --- /dev/null +++ b/docs/gallery/hitching-post/index.html @@ -0,0 +1,1114 @@ + + + + + + hitching-post — Examples — Blender Developer Tools + + + + + + + + + + + + + + + + + +
+ Examples Gallery +
+ GitHub +
+
+
+

hitching-post

+

A procedural hitching post 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: 848 tris, two materials with 262 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.460×0.194×1.260 m, LOD ratios in band (5.2 COLLAPSE more aggressive on LOD2), convex collider 144 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.
+
+ 
blender --background --python showcase/hitching-post/hitching_post.py --
+ +
+
+

A showcase piece, not an example. Procedural timber hitching post (square post, pyramidal cap, cross-arm, iron shoe, bands, and two hitching rings) 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 | 780–920 | 848 / 848 / 848 | | 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 / 0.1958 | | Materials | exactly 2 distinct, ≥24 metal faces | 2 slots, 262 metal | | UVs | in 0..1, AABB overlap ≤ 1e-5 | in range, overlap 0 | | Outer AABB | (0.460, 0.194, 1.260) m ± 0.01 | (0.4600, 0.1943, 1.2600), zmin 0 | | Collider tris | ≤ 180 | 144 | | Export | written, size > 0 | 73164 / 73164 / 73160 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 4 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 hitching_post.py --
+blender --background --python hitching_post.py -- --skip-decimate
+blender --background --python hitching_post.py -- --output hitching-post.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 wood/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/hitching-post/hitching_post.py + View on GitHub → +
+ 
"""Game-ready hitching post — a showcase piece, not an example.
+
+Asserts budget conformance of a procedural timber hitching post (square
+post, pyramidal cap, cross-arm, iron shoe, bands, and hitching rings)
+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 hitching_post.py --
+    blender --background --python hitching_post.py -- --skip-decimate
+    blender --background --python hitching_post.py -- --output hitching-post.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
+
+POST_W = 0.125
+POST_H = 1.16
+CAP_H = 0.10
+SHOE_H = 0.050
+SHOE_SCALE = 1.34
+ARM_Z = 0.90
+ARM_L = 0.46
+ARM_Y = 0.056
+ARM_ZTH = 0.056
+RING_MAJOR = 0.058
+RING_MINOR = 0.011
+BAND_H = 0.030
+BAND_T = 0.012
+BAND_ZS = (0.20, 0.52)
+
+BBOX_TOL = 0.01
+OUTER_SIZE = (0.460, 0.194, 1.260)
+BASE_TRIS_MIN = 780
+BASE_TRIS_MAX = 920
+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 = 180
+BAKE_RES = 256
+CAGE_EXTRUSION = 0.08
+METAL_FACES_MIN = 24
+WOOD_FACES_MIN = 12
+
+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_oriented_box(bm, a, b, scale_xy, mat_idx):
+    a = Vector(a)
+    b = Vector(b)
+    delta = b - a
+    length = delta.length
+    if length < 1e-8:
+        return []
+    quat = Vector((0.0, 0.0, 1.0)).rotation_difference(delta.normalized())
+    eul = quat.to_euler("XYZ")
+    return add_box(
+        bm,
+        ((a + b) * 0.5),
+        (scale_xy[0], scale_xy[1], length),
+        mat_idx,
+        euler=(eul.x, eul.y, eul.z),
+    )
+
+
+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_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 add_rim(bm, loc, major, minor, mat_idx, euler=(0.0, 0.0, 0.0)):
+    n_major = 14
+    n_minor = 7
+    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 add_square_band(bm, z, half, t, h, mat_idx):
+    metal = []
+    metal.extend(add_box(bm, (0.0, half + t / 2.0, z), (2.0 * half + 2.0 * t, t, h), mat_idx))
+    metal.extend(add_box(bm, (0.0, -(half + t / 2.0), z), (2.0 * half + 2.0 * t, t, h), mat_idx))
+    metal.extend(add_box(bm, (half + t / 2.0, 0.0, z), (t, 2.0 * half, h), mat_idx))
+    metal.extend(add_box(bm, (-(half + t / 2.0), 0.0, z), (t, 2.0 * half, h), mat_idx))
+    return metal
+
+
+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_hitching_post_mesh(name, bevel_offset, bevel_segments):
+    bm = bmesh.new()
+    try:
+        wood = []
+        metal = []
+        half = POST_W / 2.0
+
+        wood.extend(
+            add_box(
+                bm,
+                (0.0, 0.0, POST_H / 2.0),
+                (POST_W, POST_W, POST_H),
+                WOOD_IDX,
+            )
+        )
+        wood.extend(
+            add_cone(
+                bm,
+                (0.0, 0.0, POST_H + CAP_H / 2.0),
+                POST_W * 0.78,
+                0.012,
+                CAP_H,
+                4,
+                WOOD_IDX,
+                euler=(0.0, 0.0, math.pi / 4.0),
+            )
+        )
+        wood.extend(
+            add_box(
+                bm,
+                (0.0, 0.0, ARM_Z),
+                (ARM_L, ARM_Y, ARM_ZTH),
+                WOOD_IDX,
+            )
+        )
+
+        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
+
+        metal.extend(
+            add_box(
+                bm,
+                (0.0, 0.0, SHOE_H / 2.0),
+                (POST_W * SHOE_SCALE, POST_W * SHOE_SCALE, SHOE_H),
+                METAL_IDX,
+            )
+        )
+        for z in BAND_ZS:
+            metal.extend(add_square_band(bm, z, half, BAND_T, BAND_H, METAL_IDX))
+
+        ring_y = -(max(POST_W, ARM_Y) / 2.0 + RING_MINOR + 0.006)
+        for sx in (-ARM_L * 0.32, ARM_L * 0.32):
+            metal.extend(
+                add_box(
+                    bm,
+                    (sx, ring_y + RING_MINOR + 0.010, ARM_Z),
+                    (0.018, 0.022, 0.018),
+                    METAL_IDX,
+                )
+            )
+            metal.extend(
+                add_rim(
+                    bm,
+                    (sx, ring_y - RING_MAJOR * 0.35, ARM_Z - RING_MAJOR * 0.15),
+                    RING_MAJOR,
+                    RING_MINOR,
+                    METAL_IDX,
+                    euler=(math.pi / 2.0, 0.0, 0.0),
+                )
+            )
+
+        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]
+        rcx = 0.5 * (min(xs) + max(xs))
+        rcy = 0.5 * (min(ys) + max(ys))
+        zmin = min(zs)
+        for v in bm.verts:
+            v.co.x -= rcx
+            v.co.y -= rcy
+            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("HitchPostNrm", 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_hitching_post_mesh("HitchPostLow", bevel_offset=0.004, bevel_segments=2)
+    high = build_hitching_post_mesh("HitchPostHigh", bevel_offset=0.004, bevel_segments=4)
+    wood = principled("HitchPostWood", (0.36, 0.19, 0.07, 1.0), 0.0, 0.60)
+    metal = principled("HitchPostIron", (0.14, 0.145, 0.155, 1.0), 1.0, 0.38)
+    assign_slots(low, wood, metal)
+    assign_slots(high, wood, metal)
+
+    if low.data is None or len(low.data.polygons) < 6:
+        return fail("hitching post 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("hitching post has no UV layer", 3), None, None, None, None, None
+    bake_result = bake_normal(high, low)
+
+    lod1 = make_lod(low, "HitchPostLOD1", LOD1_TARGET, skip_decimate)
+    lod2 = make_lod(low, "HitchPostLOD2", 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_hitching_post_mesh(
+        "HitchPostColSrc", bevel_offset=0.0, bevel_segments=1
+    )
+    collider = convex_hull_collider(collider_src, "HitchPostCollider")
+    bpy.data.objects.remove(collider_src, do_unlink=True)
+    col_tris = triangle_count(collider.data)
+
+    export_path = os.path.join(
+        tempfile.gettempdir(),
+        f"bdt_hitching_post_{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 idx_counts.get(WOOD_IDX, 0) < WOOD_FACES_MIN:
+        return fail(
+            f"wood faces {idx_counts.get(WOOD_IDX, 0)} < {WOOD_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(-18.0)
+    low.rotation_euler.x = math.radians(0.0)
+
+    floor_me = bpy.data.meshes.new("Floor")
+    bm = bmesh.new()
+    try:
+        bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0)
+        bm.to_mesh(floor_me)
+    finally:
+        bm.free()
+    fmat = bpy.data.materials.new("Floor")
+    fmat.use_nodes = True
+    fb = fmat.node_tree.nodes["Principled BSDF"]
+    fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0)
+    fb.inputs["Roughness"].default_value = 0.7
+    floor_me.materials.append(fmat)
+    floor = bpy.data.objects.new("Floor", floor_me)
+    scene.collection.objects.link(floor)
+    wall = bpy.data.objects.new("Wall", floor_me.copy())
+    wall.location = (0.0, 8.5, 0.0)
+    wall.rotation_euler = (math.radians(90), 0.0, 0.0)
+    scene.collection.objects.link(wall)
+
+    world = bpy.data.worlds.new("World")
+    world.use_nodes = True
+    world.node_tree.nodes["Background"].inputs["Color"].default_value = (
+        0.02, 0.021, 0.025, 1.0,
+    )
+    scene.world = world
+
+    def light(name, loc, energy, size, col, rot):
+        ld = bpy.data.lights.new(name, "AREA")
+        ld.energy = energy
+        ld.size = size
+        ld.color = col
+        ob = bpy.data.objects.new(name, ld)
+        ob.location = loc
+        ob.rotation_euler = tuple(math.radians(a) for a in rot)
+        scene.collection.objects.link(ob)
+
+    light("Key", (-3.6, -5.0, 5.4), 660.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36))
+    light("Fill", (5.0, -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 = (2.25, -3.12, 1.22)
+    scene.collection.objects.link(cam)
+    aim = bpy.data.objects.new("Aim", None)
+    aim.location = (0.0, 0.0, 0.63)
+    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("hitching-post 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 db1eb35..bf147e1 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" /> - 66 examples + 68 examples
@@ -1050,6 +1050,28 @@

water-trough

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

hitching-post

+

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

+

witnesses Recomputed: 848 tris, two materials with 262 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.460×0.194×1.260 m, LOD ratios in band (5.2 COLLAPSE more aggressive on LOD2), convex collider 144 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.

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

grindstone

+

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

+

witnesses Recomputed: 1604 tris, three materials with 80 metal and 26 stone faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.630×0.615×0.575 m, LOD ratios in band, convex collider 130 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.

+ View example +
+
diff --git a/showcase/gallery.json b/showcase/gallery.json index 4049d69..ee6f359 100644 --- a/showcase/gallery.json +++ b/showcase/gallery.json @@ -184,6 +184,30 @@ "mesh", "export" ] + }, + { + "name": "hitching-post", + "dir": "showcase/hitching-post", + "teaches": "A procedural hitching post through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.", + "witnessesFix": "Recomputed: 848 tris, two materials with 262 metal faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.460×0.194×1.260 m, LOD ratios in band (5.2 COLLAPSE more aggressive on LOD2), convex collider 144 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.", + "hero": "docs/gallery/assets/hitching-post-hero.webp", + "preview": "showcase/hitching-post/preview.webp", + "tags": [ + "mesh", + "export" + ] + }, + { + "name": "grindstone", + "dir": "showcase/grindstone", + "teaches": "A procedural grindstone on a timber trestle through UVs, bake, LOD, collider, and Unity glTF, asserting recomputed budgets rather than an API contract.", + "witnessesFix": "Recomputed: 1604 tris, three materials with 80 metal and 26 stone faces, UVs in 0..1 with zero AABB overlap, outer AABB 0.630×0.615×0.575 m, LOD ratios in band, convex collider 130 tris, non-empty glTF. --skip-decimate exits 9 on the LOD1 ratio budget.", + "hero": "docs/gallery/assets/grindstone-hero.webp", + "preview": "showcase/grindstone/preview.webp", + "tags": [ + "mesh", + "export" + ] } ] } diff --git a/showcase/grindstone/README.md b/showcase/grindstone/README.md new file mode 100644 index 0000000..31519a0 --- /dev/null +++ b/showcase/grindstone/README.md @@ -0,0 +1,73 @@ +# Grindstone + +A showcase piece, not an example. Procedural grindstone (stone wheel, +timber A-frame trestle, iron axle, hubs, crank, and tray) 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 | 1480–1720 | 1604 / 1604 / 1604 | +| LOD1 ratio | 0.32–0.62 of base | 0.5000 / 0.5000 / 0.5000 | +| LOD2 ratio | 0.10–0.35 of base | 0.2195 / 0.2195 / 0.2195 | +| Materials | exactly 3 distinct, ≥24 metal and stone faces | 3 slots, 80 metal, 26 stone | +| UVs | in `0..1`, AABB overlap ≤ 1e-5 | in range, overlap 0 | +| Outer AABB | (0.630, 0.615, 0.575) m ± 0.01 | (0.6300, 0.6150, 0.5750), zmin 0 | +| Collider tris | ≤ 180 | 130 | +| Export | written, size > 0 | 123436 / 123436 / 123416 bytes | + +DECIMATE COLLAPSE triangle counts are **not** identical across series — +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 +20 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 grindstone.py -- +blender --background --python grindstone.py -- --skip-decimate +blender --background --python grindstone.py -- --output grindstone.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 ≠ 3 distinct slots, or wood/stone/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/grindstone/grindstone.py b/showcase/grindstone/grindstone.py new file mode 100644 index 0000000..d6741e0 --- /dev/null +++ b/showcase/grindstone/grindstone.py @@ -0,0 +1,828 @@ +"""Game-ready grindstone — a showcase piece, not an example. + +Asserts budget conformance of a procedural grindstone (stone wheel, +timber trestle, iron axle, hubs, and crank) after composing shipped +pipeline pieces: bmesh construction, UVs, three 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 grindstone.py -- + blender --background --python grindstone.py -- --skip-decimate + blender --background --python grindstone.py -- --output grindstone.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 + +STONE_R = 0.235 +STONE_T = 0.058 +STONE_SEGS = 24 +AXLE_Z = 0.34 +FRAME_Y = 0.175 +LEG_SPREAD = 0.28 +LEG_XY = (0.044, 0.044) +AXLE_R = 0.016 +AXLE_LEN = 0.50 +HUB_R = 0.040 +HUB_T = 0.026 +TRAY_L = 0.46 +TRAY_W = 0.26 +TRAY_H = 0.055 +CRANK_ARM = 0.14 +HANDLE_L = 0.10 + +BBOX_TOL = 0.01 +OUTER_SIZE = (0.630, 0.615, 0.575) +BASE_TRIS_MIN = 1480 +BASE_TRIS_MAX = 1720 +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 = 3 +UV_EPS = 1e-4 +UV_OVERLAP_MAX = 1e-5 +COLLIDER_TRIS_MAX = 180 +BAKE_RES = 256 +CAGE_EXTRUSION = 0.08 +METAL_FACES_MIN = 24 +WOOD_FACES_MIN = 12 +STONE_FACES_MIN = 24 + +WOOD_IDX = 0 +STONE_IDX = 1 +METAL_IDX = 2 + + +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_oriented_box(bm, a, b, scale_xy, mat_idx): + a = Vector(a) + b = Vector(b) + delta = b - a + length = delta.length + if length < 1e-8: + return [] + quat = Vector((0.0, 0.0, 1.0)).rotation_difference(delta.normalized()) + eul = quat.to_euler("XYZ") + return add_box( + bm, + ((a + b) * 0.5), + (scale_xy[0], scale_xy[1], length), + mat_idx, + euler=(eul.x, eul.y, eul.z), + ) + + +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_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_grindstone_mesh(name, bevel_offset, bevel_segments): + bm = bmesh.new() + try: + wood = [] + stone = [] + metal = [] + + for y in (-FRAME_Y, FRAME_Y): + wood.extend( + add_oriented_box( + bm, + (-LEG_SPREAD, y, 0.022), + (0.0, y, AXLE_Z), + LEG_XY, + WOOD_IDX, + ) + ) + wood.extend( + add_oriented_box( + bm, + (LEG_SPREAD, y, 0.022), + (0.0, y, AXLE_Z), + LEG_XY, + WOOD_IDX, + ) + ) + wood.extend( + add_box( + bm, + (0.0, y, 0.072), + (LEG_SPREAD * 1.55, 0.038, 0.038), + WOOD_IDX, + ) + ) + wood.extend( + add_box( + bm, + (0.0, y, AXLE_Z), + (0.090, 0.070, 0.070), + WOOD_IDX, + ) + ) + + wood.extend( + add_box( + bm, + (0.0, 0.0, 0.078), + (0.070, FRAME_Y * 2.0 + 0.04, 0.040), + WOOD_IDX, + ) + ) + wood.extend( + add_box( + bm, + (0.0, 0.0, TRAY_H / 2.0 + 0.004), + (TRAY_L, TRAY_W, TRAY_H), + WOOD_IDX, + ) + ) + wood.extend( + add_cyl( + bm, + (0.0, FRAME_Y + AXLE_LEN * 0.28, AXLE_Z + CRANK_ARM), + 0.014, + HANDLE_L, + 8, + WOOD_IDX, + euler=(math.pi / 2.0, 0.0, 0.0), + ) + ) + + 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 + + stone.extend( + add_cyl( + bm, + (0.0, 0.0, AXLE_Z), + STONE_R, + STONE_T, + STONE_SEGS, + STONE_IDX, + euler=(math.pi / 2.0, 0.0, 0.0), + ) + ) + + metal.extend( + add_cyl( + bm, + (0.0, 0.0, AXLE_Z), + AXLE_R, + AXLE_LEN, + 10, + METAL_IDX, + euler=(math.pi / 2.0, 0.0, 0.0), + ) + ) + for y in (-STONE_T / 2.0 - HUB_T / 2.0 + 0.004, STONE_T / 2.0 + HUB_T / 2.0 - 0.004): + metal.extend( + add_cyl( + bm, + (0.0, y, AXLE_Z), + HUB_R, + HUB_T, + 12, + METAL_IDX, + euler=(math.pi / 2.0, 0.0, 0.0), + ) + ) + crank_y = FRAME_Y + AXLE_LEN * 0.22 + metal.extend( + add_box( + bm, + (0.0, crank_y, AXLE_Z + CRANK_ARM / 2.0), + (0.018, 0.018, CRANK_ARM + 0.02), + METAL_IDX, + ) + ) + metal.extend( + add_cyl( + bm, + (0.0, crank_y, AXLE_Z + CRANK_ARM), + 0.010, + HANDLE_L * 0.55, + 8, + METAL_IDX, + euler=(math.pi / 2.0, 0.0, 0.0), + ) + ) + for y in (-FRAME_Y, FRAME_Y): + for x in (-LEG_SPREAD, LEG_SPREAD): + metal.extend( + add_box( + bm, + (x, y, 0.018), + (0.070, 0.070, 0.036), + 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] + rcx = 0.5 * (min(xs) + max(xs)) + rcy = 0.5 * (min(ys) + max(ys)) + zmin = min(zs) + for v in bm.verts: + v.co.x -= rcx + v.co.y -= rcy + 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, stone, metal): + mats = obj.data.materials + wanted = (wood, stone, 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("GrindstoneNrm", 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 = STONE_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_grindstone_mesh("GrindstoneLow", bevel_offset=0.004, bevel_segments=2) + high = build_grindstone_mesh("GrindstoneHigh", bevel_offset=0.004, bevel_segments=4) + wood = principled("GrindstoneWood", (0.36, 0.19, 0.07, 1.0), 0.0, 0.60) + stone = principled("GrindstoneStone", (0.46, 0.44, 0.41, 1.0), 0.0, 0.86) + metal = principled("GrindstoneIron", (0.14, 0.145, 0.155, 1.0), 1.0, 0.38) + assign_slots(low, wood, stone, metal) + assign_slots(high, wood, stone, metal) + + if low.data is None or len(low.data.polygons) < 6: + return fail("grindstone 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, stone) + if img is None: + return fail("grindstone has no UV layer", 3), None, None, None, None, None + bake_result = bake_normal(high, low) + + lod1 = make_lod(low, "GrindstoneLOD1", LOD1_TARGET, skip_decimate) + lod2 = make_lod(low, "GrindstoneLOD2", 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_grindstone_mesh( + "GrindstoneColSrc", bevel_offset=0.0, bevel_segments=1 + ) + collider = convex_hull_collider(collider_src, "GrindstoneCollider") + bpy.data.objects.remove(collider_src, do_unlink=True) + col_tris = triangle_count(collider.data) + + export_path = os.path.join( + tempfile.gettempdir(), + f"bdt_grindstone_{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 idx_counts.get(STONE_IDX, 0) < STONE_FACES_MIN: + return fail( + f"stone faces {idx_counts.get(STONE_IDX, 0)} < {STONE_FACES_MIN}", + 5, + ), None, None, None, None, None + if idx_counts.get(WOOD_IDX, 0) < WOOD_FACES_MIN: + return fail( + f"wood faces {idx_counts.get(WOOD_IDX, 0)} < {WOOD_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, stone, tex, collider + + +def wire_normal(mat, tex): + nt = mat.node_tree + bsdf = nt.nodes["Principled BSDF"] + nrm = nt.nodes.new("ShaderNodeNormalMap") + nrm.inputs["Strength"].default_value = 1.0 + nt.links.new(tex.outputs["Color"], nrm.inputs["Color"]) + nt.links.new(nrm.outputs["Normal"], bsdf.inputs["Normal"]) + + +def render_still(low, wood, tex, path, engine): + scene = bpy.context.scene + wire_normal(wood, tex) + for ob in list(scene.objects): + if ob.type == "MESH" and ob != low: + ob.hide_render = True + ob.hide_viewport = True + + low.rotation_euler.z = math.radians(-16.0) + low.rotation_euler.x = math.radians(0.0) + + floor_me = bpy.data.meshes.new("Floor") + bm = bmesh.new() + try: + bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0) + bm.to_mesh(floor_me) + finally: + bm.free() + fmat = bpy.data.materials.new("Floor") + fmat.use_nodes = True + fb = fmat.node_tree.nodes["Principled BSDF"] + fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0) + fb.inputs["Roughness"].default_value = 0.7 + floor_me.materials.append(fmat) + floor = bpy.data.objects.new("Floor", floor_me) + scene.collection.objects.link(floor) + wall = bpy.data.objects.new("Wall", floor_me.copy()) + wall.location = (0.0, 8.5, 0.0) + wall.rotation_euler = (math.radians(90), 0.0, 0.0) + scene.collection.objects.link(wall) + + world = bpy.data.worlds.new("World") + world.use_nodes = True + world.node_tree.nodes["Background"].inputs["Color"].default_value = ( + 0.02, 0.021, 0.025, 1.0, + ) + scene.world = world + + def light(name, loc, energy, size, col, rot): + ld = bpy.data.lights.new(name, "AREA") + ld.energy = energy + ld.size = size + ld.color = col + ob = bpy.data.objects.new(name, ld) + ob.location = loc + ob.rotation_euler = tuple(math.radians(a) for a in rot) + scene.collection.objects.link(ob) + + light("Key", (-3.6, -5.0, 5.4), 660.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36)) + light("Fill", (5.0, -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 = (1.48, -1.82, 0.86) + scene.collection.objects.link(cam) + aim = bpy.data.objects.new("Aim", None) + aim.location = (0.0, 0.0, 0.28) + 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, hero_mat, tex, _col = check(args.skip_decimate) + if code: + return code + if args.output: + rcode = render_still(low, hero_mat, tex, os.path.abspath(args.output), args.engine) + if rcode: + return rcode + print(f"rendered still {args.output}") + print("grindstone 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/grindstone/preview.webp b/showcase/grindstone/preview.webp new file mode 100644 index 0000000..3a1bcf8 Binary files /dev/null and b/showcase/grindstone/preview.webp differ diff --git a/showcase/hitching-post/README.md b/showcase/hitching-post/README.md new file mode 100644 index 0000000..08866a9 --- /dev/null +++ b/showcase/hitching-post/README.md @@ -0,0 +1,74 @@ +# Hitching post + +A showcase piece, not an example. Procedural timber hitching post +(square post, pyramidal cap, cross-arm, iron shoe, bands, and two +hitching rings) 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 | 780–920 | 848 / 848 / 848 | +| 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 / 0.1958 | +| Materials | exactly 2 distinct, ≥24 metal faces | 2 slots, 262 metal | +| UVs | in `0..1`, AABB overlap ≤ 1e-5 | in range, overlap 0 | +| Outer AABB | (0.460, 0.194, 1.260) m ± 0.01 | (0.4600, 0.1943, 1.2600), zmin 0 | +| Collider tris | ≤ 180 | 144 | +| Export | written, size > 0 | 73164 / 73164 / 73160 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 4 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 hitching_post.py -- +blender --background --python hitching_post.py -- --skip-decimate +blender --background --python hitching_post.py -- --output hitching-post.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 wood/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/hitching-post/hitching_post.py b/showcase/hitching-post/hitching_post.py new file mode 100644 index 0000000..b9edd1e --- /dev/null +++ b/showcase/hitching-post/hitching_post.py @@ -0,0 +1,790 @@ +"""Game-ready hitching post — a showcase piece, not an example. + +Asserts budget conformance of a procedural timber hitching post (square +post, pyramidal cap, cross-arm, iron shoe, bands, and hitching rings) +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 hitching_post.py -- + blender --background --python hitching_post.py -- --skip-decimate + blender --background --python hitching_post.py -- --output hitching-post.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 + +POST_W = 0.125 +POST_H = 1.16 +CAP_H = 0.10 +SHOE_H = 0.050 +SHOE_SCALE = 1.34 +ARM_Z = 0.90 +ARM_L = 0.46 +ARM_Y = 0.056 +ARM_ZTH = 0.056 +RING_MAJOR = 0.058 +RING_MINOR = 0.011 +BAND_H = 0.030 +BAND_T = 0.012 +BAND_ZS = (0.20, 0.52) + +BBOX_TOL = 0.01 +OUTER_SIZE = (0.460, 0.194, 1.260) +BASE_TRIS_MIN = 780 +BASE_TRIS_MAX = 920 +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 = 180 +BAKE_RES = 256 +CAGE_EXTRUSION = 0.08 +METAL_FACES_MIN = 24 +WOOD_FACES_MIN = 12 + +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_oriented_box(bm, a, b, scale_xy, mat_idx): + a = Vector(a) + b = Vector(b) + delta = b - a + length = delta.length + if length < 1e-8: + return [] + quat = Vector((0.0, 0.0, 1.0)).rotation_difference(delta.normalized()) + eul = quat.to_euler("XYZ") + return add_box( + bm, + ((a + b) * 0.5), + (scale_xy[0], scale_xy[1], length), + mat_idx, + euler=(eul.x, eul.y, eul.z), + ) + + +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_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 add_rim(bm, loc, major, minor, mat_idx, euler=(0.0, 0.0, 0.0)): + n_major = 14 + n_minor = 7 + 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 add_square_band(bm, z, half, t, h, mat_idx): + metal = [] + metal.extend(add_box(bm, (0.0, half + t / 2.0, z), (2.0 * half + 2.0 * t, t, h), mat_idx)) + metal.extend(add_box(bm, (0.0, -(half + t / 2.0), z), (2.0 * half + 2.0 * t, t, h), mat_idx)) + metal.extend(add_box(bm, (half + t / 2.0, 0.0, z), (t, 2.0 * half, h), mat_idx)) + metal.extend(add_box(bm, (-(half + t / 2.0), 0.0, z), (t, 2.0 * half, h), mat_idx)) + return metal + + +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_hitching_post_mesh(name, bevel_offset, bevel_segments): + bm = bmesh.new() + try: + wood = [] + metal = [] + half = POST_W / 2.0 + + wood.extend( + add_box( + bm, + (0.0, 0.0, POST_H / 2.0), + (POST_W, POST_W, POST_H), + WOOD_IDX, + ) + ) + wood.extend( + add_cone( + bm, + (0.0, 0.0, POST_H + CAP_H / 2.0), + POST_W * 0.78, + 0.012, + CAP_H, + 4, + WOOD_IDX, + euler=(0.0, 0.0, math.pi / 4.0), + ) + ) + wood.extend( + add_box( + bm, + (0.0, 0.0, ARM_Z), + (ARM_L, ARM_Y, ARM_ZTH), + WOOD_IDX, + ) + ) + + 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 + + metal.extend( + add_box( + bm, + (0.0, 0.0, SHOE_H / 2.0), + (POST_W * SHOE_SCALE, POST_W * SHOE_SCALE, SHOE_H), + METAL_IDX, + ) + ) + for z in BAND_ZS: + metal.extend(add_square_band(bm, z, half, BAND_T, BAND_H, METAL_IDX)) + + ring_y = -(max(POST_W, ARM_Y) / 2.0 + RING_MINOR + 0.006) + for sx in (-ARM_L * 0.32, ARM_L * 0.32): + metal.extend( + add_box( + bm, + (sx, ring_y + RING_MINOR + 0.010, ARM_Z), + (0.018, 0.022, 0.018), + METAL_IDX, + ) + ) + metal.extend( + add_rim( + bm, + (sx, ring_y - RING_MAJOR * 0.35, ARM_Z - RING_MAJOR * 0.15), + RING_MAJOR, + RING_MINOR, + METAL_IDX, + euler=(math.pi / 2.0, 0.0, 0.0), + ) + ) + + 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] + rcx = 0.5 * (min(xs) + max(xs)) + rcy = 0.5 * (min(ys) + max(ys)) + zmin = min(zs) + for v in bm.verts: + v.co.x -= rcx + v.co.y -= rcy + 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("HitchPostNrm", 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_hitching_post_mesh("HitchPostLow", bevel_offset=0.004, bevel_segments=2) + high = build_hitching_post_mesh("HitchPostHigh", bevel_offset=0.004, bevel_segments=4) + wood = principled("HitchPostWood", (0.36, 0.19, 0.07, 1.0), 0.0, 0.60) + metal = principled("HitchPostIron", (0.14, 0.145, 0.155, 1.0), 1.0, 0.38) + assign_slots(low, wood, metal) + assign_slots(high, wood, metal) + + if low.data is None or len(low.data.polygons) < 6: + return fail("hitching post 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("hitching post has no UV layer", 3), None, None, None, None, None + bake_result = bake_normal(high, low) + + lod1 = make_lod(low, "HitchPostLOD1", LOD1_TARGET, skip_decimate) + lod2 = make_lod(low, "HitchPostLOD2", 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_hitching_post_mesh( + "HitchPostColSrc", bevel_offset=0.0, bevel_segments=1 + ) + collider = convex_hull_collider(collider_src, "HitchPostCollider") + bpy.data.objects.remove(collider_src, do_unlink=True) + col_tris = triangle_count(collider.data) + + export_path = os.path.join( + tempfile.gettempdir(), + f"bdt_hitching_post_{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 idx_counts.get(WOOD_IDX, 0) < WOOD_FACES_MIN: + return fail( + f"wood faces {idx_counts.get(WOOD_IDX, 0)} < {WOOD_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(-18.0) + low.rotation_euler.x = math.radians(0.0) + + floor_me = bpy.data.meshes.new("Floor") + bm = bmesh.new() + try: + bmesh.ops.create_grid(bm, x_segments=1, y_segments=1, size=14.0) + bm.to_mesh(floor_me) + finally: + bm.free() + fmat = bpy.data.materials.new("Floor") + fmat.use_nodes = True + fb = fmat.node_tree.nodes["Principled BSDF"] + fb.inputs["Base Color"].default_value = (0.03, 0.032, 0.037, 1.0) + fb.inputs["Roughness"].default_value = 0.7 + floor_me.materials.append(fmat) + floor = bpy.data.objects.new("Floor", floor_me) + scene.collection.objects.link(floor) + wall = bpy.data.objects.new("Wall", floor_me.copy()) + wall.location = (0.0, 8.5, 0.0) + wall.rotation_euler = (math.radians(90), 0.0, 0.0) + scene.collection.objects.link(wall) + + world = bpy.data.worlds.new("World") + world.use_nodes = True + world.node_tree.nodes["Background"].inputs["Color"].default_value = ( + 0.02, 0.021, 0.025, 1.0, + ) + scene.world = world + + def light(name, loc, energy, size, col, rot): + ld = bpy.data.lights.new(name, "AREA") + ld.energy = energy + ld.size = size + ld.color = col + ob = bpy.data.objects.new(name, ld) + ob.location = loc + ob.rotation_euler = tuple(math.radians(a) for a in rot) + scene.collection.objects.link(ob) + + light("Key", (-3.6, -5.0, 5.4), 660.0, 4.0, (1.0, 0.94, 0.86), (50, 0, -36)) + light("Fill", (5.0, -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 = (2.25, -3.12, 1.22) + scene.collection.objects.link(cam) + aim = bpy.data.objects.new("Aim", None) + aim.location = (0.0, 0.0, 0.63) + 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("hitching-post 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/hitching-post/preview.webp b/showcase/hitching-post/preview.webp new file mode 100644 index 0000000..1223411 Binary files /dev/null and b/showcase/hitching-post/preview.webp differ diff --git a/tests/smoke/catalog.json b/tests/smoke/catalog.json index a396505..05cf588 100644 --- a/tests/smoke/catalog.json +++ b/tests/smoke/catalog.json @@ -88,5 +88,7 @@ {"name": "park-bench", "script": "showcase/park-bench/park_bench.py"}, {"name": "wheelbarrow", "script": "showcase/wheelbarrow/wheelbarrow.py"}, {"name": "anvil", "script": "showcase/anvil/anvil.py"}, - {"name": "water-trough", "script": "showcase/water-trough/water_trough.py"} + {"name": "water-trough", "script": "showcase/water-trough/water_trough.py"}, + {"name": "hitching-post", "script": "showcase/hitching-post/hitching_post.py"}, + {"name": "grindstone", "script": "showcase/grindstone/grindstone.py"} ]