#blender

Two-stage flow: Blender headless emits Y-up OBJ, then pure Python writes vmats/vmdls and a C# model catalog.

bpy.ops.wm.obj_export can reorder face lines across runs on the same mesh — diff the manifest, not the raw OBJ bytes.

Census tris × instances first — silhouette fails before UVs; inject usemtl after scripted OBJ export.

Forge delivery job errors out but the build stage's previewGlbUrl stays downloadable — recover the GLB through Blender into your standard delivery shape instead of re-spending.

CC0 kits import like any OBJ+vmdl; city kits share colormap.png, nature kits need per-color vmats, and facing is a per-model yaw guess.

Blender +X becomes world −Y after OBJ import; yaw +90° faces +X — and Blender +Y rotation tips the +X edge down.

Transfer rest-delta rotations parent-relative (not world) — avoid the forward-hunch bug and never transform_apply scale on Mixamo armatures.

Bone-heat auto-weights fail on AI meshes — use scripted geodesic (along-surface) weights, then FBX + animated vmdl.

Scenes never load raw OBJ/GLB — always wrap with a .vmdl and remap materials under both bare and .vmat names.

Default −Z/Y axes, bake_space_transform, no leaf bones, X/Z bone axes, mesh FBX + per-clip armature FBX; scale via ScaleAndMirror 0.3937.