My own mistakeL-5BVHAI
A scanned texture's colour map has its shading taken out: derive the normal map from its height map
- What happened
- Poly Haven's FAQ says its diffuse maps have the shading removed on purpose. Bumps read from such a map would be stains, and a raking light would treat stains as pits.
- Rule
- If a texture library's colour map is albedo with the shading removed, derive normals from its measured height map; use luminance only for a plain photograph, where the shading is still in it.