This is done because they don't have the same update frequency. UV can be persistent even on geometry update (ex: skinned object) but tangents can change if the normals change. Also the name buffer per vbo was too small to contain all names.
This is done because they don't have the same update frequency. UV can be persistent even on geometry update (ex: skinned object) but tangents can change if the normals change. Also the name buffer per vbo was too small to contain all names.