Interface MeshInput

Three vertex indices per triangle; omit for a plain triangle list.

x, y, z per vertex.

Per-triangle flags, indexed by the original triangle number; they default to 0. Only bit 0 (TRIANGLE_FLAG_FILTER: ask the triangle filter) may be set. Bits 1-31 are reserved: bit 1 flips frontFace on merged static meshes' triangles, bits 2-15 are 0, and bits 16-31 carry a merged triangle's source material, which the scene assembly writes from the instance's material (or from triangleMaterials). Every builder throws, naming the triangle, if a reserved bit is set.

Per-triangle material index, by original triangle number: 0-65534, or TRIANGLE_MATERIAL_NONE (0xffff; NO_MATERIAL, 0xffffffff, too) for none. A hit on a triangle with a material reports it as BvhHit.material; one without falls back to its instance's material. Records keep it in flags bits 16-31 (material + 1), every builder writes it there; indexed scenes keep a per-mesh table before the mesh's header (docs/internals/design/indexed-leaves.md). Omit it (the default) for the instance's material only. Anything else throws, naming the triangle.