Self shadowed bump map
From polycount
Self-Shadowed Bump Map
This is a Normal Map variant that contains directional ambient occlusion information in the map, used in Valve's Source engine for self-shadowed bump mapping. See Valve's white paper Efficient Self-Shadowed Radiosity Normal Mapping.
SSbump Generator is a tool for generating Self-Shadowed Bump Maps from existing height maps or normal maps.
XNormal when properly configured can generate SSBump textures from a highpoly source, as explained in this Facepunch thread.
