Root cause: ALL 12 faces in cube.obj had reversed winding order. This caused every face normal to point inward, breaking: - Diffuse lighting (NdotL < 0 → no light on any face) - Shadow bias (slope-dependent bias used wrong NdotL) - Shadow self-shadowing (both sides rendered with CULL_NONE) Fix: reversed all face indices to correct CCW winding: - Back face: f 1 4 3, f 1 3 2 (was f 1 2 3, f 1 3 4) - Front face: f 5 6 7, f 5 7 8 (was f 5 7 6, f 5 8 7) - Left/Right/Bottom/Top: all reversed Now MeshMath.ComputeFaceNormal produces correct outward normals. Normal flip in shader (dot(N,V) < 0) is still kept as safety for double-sided rendering, but cubes now have correct normals natively.
669 B
669 B