Rendered headless by the example itself — click to zoom.
+
+ Source
+
+ """Game-ready iron cauldron — a showcase piece, not an example.
+
+Asserts budget conformance of a procedural hanging cauldron 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 iron_cauldron.py --
+ blender --background --python iron_cauldron.py -- --skip-decimate
+ blender --background --python iron_cauldron.py -- --output cauldron.png
+"""
+import argparse
+import math
+import os
+import sys
+import tempfile
+import traceback
+
+import bmesh
+import bpy
+from mathutils import Euler, Vector
+
+# Showcase lives at repo-root/showcase/, not under examples/. The framing
+# helper is the repo's only shared import and lives next to the examples;
+# resolve the repo root so we do not move gallery_framing.py.
+_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
+
+POT_H = 0.26
+POT_Z0 = 0.15
+POT_THICK = 0.016
+N_AROUND = 16
+N_RINGS = 5
+R_BOT = 0.065
+R_MID = 0.175
+R_TOP = 0.135
+APEX_Z = 0.78
+TRIPOD_R = 0.30
+BAIL_SEGS = 10
+BAIL_R = 0.010
+BBOX_TOL = 0.01
+# Fitted after locking geometry. Recomputed from bound_box.
+OUTER_SIZE = (0.572, 0.558, 0.786)
+
+BASE_TRIS_MIN = 6850
+BASE_TRIS_MAX = 7200
+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):
+ # Duplicated from snippets/lod_chain.py / decimate_to_budget.py (not a package).
+ 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 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_cone_between(bm, a, b, r1, r2, segments, 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_cone(
+ bm, (a + b) * 0.5, r1, r2, length, segments, mat_idx,
+ euler=(eul.x, eul.y, eul.z),
+ )
+
+
+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 = list(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_cylinder(bm, loc, radius, depth, segments, mat_idx, euler=(0.0, 0.0, 0.0)):
+ return add_cone(bm, loc, radius, radius, depth, segments, mat_idx, euler=euler)
+
+
+def add_rim(bm, loc, major, minor, mat_idx, euler=(0.0, 0.0, 0.0)):
+ n_major = 12
+ n_minor = 6
+ 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)
+ for i in range(n_major):
+ i2 = (i + 1) % n_major
+ for j in range(n_minor):
+ j2 = (j + 1) % n_minor
+ face = bm.faces.new(
+ (rings[i][j], rings[i2][j], rings[i2][j2], rings[i][j2])
+ )
+ face.material_index = mat_idx
+ verts = [v for ring in rings for v in ring]
+ rot = Euler(euler).to_matrix()
+ origin = Vector(loc)
+ for v in verts:
+ v.co = rot @ v.co + origin
+ return verts
+
+
+def pack_uvs(bm, margin=0.08):
+ uv = bm.loops.layers.uv.new("UVMap")
+ faces = list(bm.faces)
+ n = len(faces)
+ cols = max(1, math.ceil(math.sqrt(n)))
+ rows = max(1, math.ceil(n / cols))
+ cell_w = 1.0 / cols
+ cell_h = 1.0 / rows
+ pad_u = margin * cell_w * 0.5
+ pad_v = margin * cell_h * 0.5
+ usable_w = cell_w - 2.0 * pad_u
+ usable_h = cell_h - 2.0 * pad_v
+ for i, face in enumerate(faces):
+ col = i % cols
+ row = i // cols
+ nrm = face.normal
+ ax = abs(nrm.x)
+ ay = abs(nrm.y)
+ az = abs(nrm.z)
+ coords = []
+ for loop in face.loops:
+ co = loop.vert.co
+ if az >= ax and az >= ay:
+ coords.append((co.x, co.y))
+ elif ax >= ay:
+ coords.append((co.y, co.z))
+ else:
+ coords.append((co.x, co.z))
+ xs = [c[0] for c in coords]
+ ys = [c[1] for c in coords]
+ minx, maxx = min(xs), max(xs)
+ miny, maxy = min(ys), max(ys)
+ dx = max(maxx - minx, 1e-8)
+ dy = max(maxy - miny, 1e-8)
+ origin_u = col * cell_w + pad_u
+ origin_v = row * cell_h + pad_v
+ for loop, (x, y) in zip(face.loops, coords):
+ loop[uv].uv = (
+ origin_u + (x - minx) / dx * usable_w,
+ origin_v + (y - miny) / dy * usable_h,
+ )
+
+
+def pot_radius(z_local):
+ t = max(0.0, min(1.0, z_local / POT_H))
+ return (1.0 - t) ** 2 * R_BOT + 2.0 * t * (1.0 - t) * (R_MID * 1.35) + t ** 2 * R_TOP
+
+
+def build_cauldron_mesh(name, bevel_offset, bevel_segments):
+ bm = bmesh.new()
+ wood_verts = []
+ metal_faces = set()
+ pot_verts = []
+ try:
+ zs = [POT_H * i / (N_RINGS - 1) for i in range(N_RINGS)]
+ gap = -0.06
+ for i in range(N_AROUND):
+ a0 = 2.0 * math.pi * i / N_AROUND
+ a1 = 2.0 * math.pi * (i + 1.0 - gap) / N_AROUND
+ outer = []
+ inner = []
+ for z_local in zs:
+ z = POT_Z0 + z_local
+ r = pot_radius(z_local)
+ ov = (
+ bm.verts.new((r * math.cos(a0), r * math.sin(a0), z)),
+ bm.verts.new((r * math.cos(a1), r * math.sin(a1), z)),
+ )
+ ri = max(r - POT_THICK, 0.02)
+ iv = (
+ bm.verts.new((ri * math.cos(a0), ri * math.sin(a0), z)),
+ bm.verts.new((ri * math.cos(a1), ri * math.sin(a1), z)),
+ )
+ outer.append(ov)
+ inner.append(iv)
+ pot_verts.extend(ov)
+ pot_verts.extend(iv)
+ for k in range(N_RINGS - 1):
+ o0a, o0b = outer[k]
+ o1a, o1b = outer[k + 1]
+ i0a, i0b = inner[k]
+ i1a, i1b = inner[k + 1]
+ for vs in (
+ (o0a, o1a, o1b, o0b),
+ (i0b, i1b, i1a, i0a),
+ (o0a, i0a, i1a, o1a),
+ (o0b, o1b, i1b, i0b),
+ ):
+ face = bm.faces.new(vs)
+ face.material_index = METAL_IDX
+ rim = bm.faces.new((outer[-1][0], outer[-1][1], inner[-1][1], inner[-1][0]))
+ rim.material_index = METAL_IDX
+ bot = bm.faces.new((outer[0][1], outer[0][0], inner[0][0], inner[0][1]))
+ bot.material_index = METAL_IDX
+
+ before = set(bm.faces)
+ add_cylinder(
+ bm,
+ (0.0, 0.0, POT_Z0 + POT_THICK * 0.6),
+ pot_radius(0.0) - POT_THICK * 0.2,
+ POT_THICK * 1.2,
+ 16,
+ METAL_IDX,
+ )
+ mouth_z = POT_Z0 + POT_H
+ add_rim(bm, (0.0, 0.0, mouth_z), R_TOP + 0.008, 0.012, METAL_IDX)
+ ear_x = R_TOP + 0.012
+ for sign in (-1.0, 1.0):
+ add_box(bm, (sign * ear_x, 0.0, mouth_z - 0.01), (0.024, 0.030, 0.040), METAL_IDX)
+ add_rim(
+ bm,
+ (sign * (ear_x + 0.004), 0.0, mouth_z + 0.008),
+ 0.014,
+ 0.005,
+ METAL_IDX,
+ euler=(math.radians(90.0), 0.0, 0.0),
+ )
+ bail_major = ear_x + 0.004
+ bail_pts = []
+ for i in range(BAIL_SEGS + 1):
+ t = math.pi * i / BAIL_SEGS
+ bail_pts.append(
+ (
+ bail_major * math.cos(t),
+ 0.0,
+ mouth_z + 0.008 + bail_major * math.sin(t),
+ )
+ )
+ for a, b in zip(bail_pts, bail_pts[1:]):
+ add_oriented_box(bm, a, b, (BAIL_R * 2.0, BAIL_R * 2.0), METAL_IDX)
+ metal_faces.update(set(bm.faces) - before)
+
+ pole_feet = []
+ for i in range(3):
+ ang = i * (2.0 * math.pi / 3.0) + math.radians(18.0)
+ foot = Vector((TRIPOD_R * math.cos(ang), TRIPOD_R * math.sin(ang), 0.016))
+ apex = Vector((0.0, 0.0, APEX_Z))
+ pole_feet.append(foot)
+ wood_verts.extend(add_cone_between(bm, foot, apex, 0.028, 0.018, 8, WOOD_IDX))
+ before = set(bm.faces)
+ add_cone_between(
+ bm,
+ foot + Vector((0.0, 0.0, 0.008)),
+ foot - Vector((0.0, 0.0, 0.014)),
+ 0.032,
+ 0.032,
+ 8,
+ METAL_IDX,
+ )
+ metal_faces.update(set(bm.faces) - before)
+
+ wood_verts.extend(add_cylinder(bm, (0.0, 0.0, APEX_Z - 0.02), 0.042, 0.055, 10, WOOD_IDX))
+ before = set(bm.faces)
+ hook_z1 = APEX_Z - 0.055
+ bail_peak = mouth_z + 0.008 + bail_major
+ add_cone_between(
+ bm,
+ (0.0, 0.0, hook_z1),
+ (0.0, 0.0, bail_peak + 0.012),
+ 0.010,
+ 0.010,
+ 8,
+ METAL_IDX,
+ )
+ add_rim(
+ bm,
+ (0.0, 0.0, bail_peak + 0.004),
+ 0.018,
+ 0.006,
+ METAL_IDX,
+ euler=(math.radians(90.0), 0.0, 0.0),
+ )
+ metal_faces.update(set(bm.faces) - before)
+
+ if bevel_offset > 0.0:
+ edges = list({e for v in pot_verts + wood_verts for e in v.link_edges if v.is_valid})
+ if edges:
+ bmesh.ops.bevel(
+ bm,
+ geom=edges,
+ offset=bevel_offset,
+ segments=bevel_segments,
+ profile=0.5,
+ affect="EDGES",
+ clamp_overlap=True,
+ )
+
+ pack_uvs(bm)
+ bmesh.ops.recalc_face_normals(bm, faces=list(bm.faces))
+ for face in bm.faces:
+ face.smooth = True
+ for edge in bm.edges:
+ edge.smooth = True
+ if edge.is_manifold and len(edge.link_faces) == 2:
+ if edge.calc_face_angle() > math.radians(35.0):
+ edge.smooth = False
+ for f in metal_faces:
+ if f.is_valid:
+ f.material_index = METAL_IDX
+ me = bpy.data.meshes.new(name)
+ bm.to_mesh(me)
+ me.update()
+ finally:
+ bm.free()
+ obj = bpy.data.objects.new(name, me)
+ bpy.context.collection.objects.link(obj)
+ return obj
+
+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
+ if len(mats) == 0:
+ mats.append(wood)
+ mats.append(metal)
+ return
+ mats[0] = wood
+ if len(mats) == 1:
+ mats.append(metal)
+ else:
+ mats[1] = metal
+
+
+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):
+ # Duplicated from snippets/convex_hull_collider.py (not a package).
+ 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):
+ # Adapted from snippets/setup_bake_target_image.py — do not replace slots.
+ if not obj.data.uv_layers:
+ return None, None
+ img = bpy.data.images.new("CauldronNrm", 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):
+ # Duplicated from snippets/bake_normal_high_to_low.py (not a package).
+ scene = bpy.context.scene
+ scene.render.engine = "CYCLES"
+ scene.cycles.device = "CPU"
+ scene.cycles.samples = 1
+ scene.cycles.use_denoising = False
+ for ob in bpy.context.view_layer.objects:
+ ob.select_set(False)
+ 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):
+ # Duplicated from snippets/export_preset_unity.py (not a package).
+ for ob in bpy.context.view_layer.objects:
+ ob.select_set(False)
+ 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_cauldron_mesh("CauldronLow", bevel_offset=0.003, bevel_segments=2)
+ high = build_cauldron_mesh("CauldronHigh", bevel_offset=0.003, bevel_segments=4)
+ wood = principled("TripodWood", (0.38, 0.22, 0.09, 1.0), 0.0, 0.58)
+ metal = principled("CauldronIron", (0.22, 0.23, 0.24, 1.0), 1.0, 0.42)
+ assign_slots(low, wood, metal)
+ assign_slots(high, wood, metal)
+
+ if low.data is None or len(low.data.polygons) < 6:
+ return fail("cauldron 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("cauldron has no UV layer", 3), None, None, None, None, None
+ bake_result = bake_normal(high, low)
+
+ lod1 = make_lod(low, "CauldronLOD1", LOD1_TARGET, skip_decimate)
+ lod2 = make_lod(low, "CauldronLOD2", 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_cauldron_mesh("CauldronColSrc", bevel_offset=0.0, bevel_segments=1)
+ collider = convex_hull_collider(collider_src, "CauldronCollider")
+ bpy.data.objects.remove(collider_src, do_unlink=True)
+ col_tris = triangle_count(collider.data)
+
+ export_path = os.path.join(
+ tempfile.gettempdir(),
+ f"bdt_iron_cauldron_{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(-28.0)
+ low.rotation_euler.x = math.radians(4.0)
+
+ 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 = (1.55, -2.05, 1.35)
+ scene.collection.objects.link(cam)
+ aim = bpy.data.objects.new("Aim", None)
+ aim.location = (0.0, 0.0, 0.38)
+ 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("iron-cauldron 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)
+
+
+