Design Nomenclature / Surface & Material
Curvature map
Also called curvature, convexity map, edge map
A texture recording the sign and magnitude of surface curvature per texel: convex edges above mid grey, concave creases below it, flat ground at it. Baked from the mesh, it is the usual driver for edge wear and crevice dirt, because both follow the form's curvature rather than any lighting term.
In practice
A cavity map is roughly this map with the convex half discarded, which is why the two get used interchangeably and shouldn't be. Baked curvature is scale-dependent — it answers at the ray distance it was baked with and at no other.
Not to be confused with
- Cavity mapA texture recording concavity at detail scale — the tight creases, pits, and panel lines, not the form. Usually multiplied into diffuse or specular to suggest the dirt and light loss that collect in a crevice. Narrower and higher in frequency than ambient occlusion, which measures hemispherical visibility at form scale.
- Ambient occlusionThe fraction of the hemisphere above a point blocked by nearby geometry — a purely geometric visibility term, no light involved. As a material channel it attenuates ambient diffuse in creases. Physically it is a coarse stand-in for the interreflection a GI solver computes properly, so under real GI it double-darkens.