Genma Saotome, on 03 December 2016 - 02:24 PM, said:
It is possible in current MSTS Shape format. Don't know if it works properly in MSTS, but I saw some .s files with more that one material for vertex.
In prim_states define more than one texture:
prim_state mtl_name ( x x tex_idxs ( num_textures texture1 texture2 ... ) x x x x x )
And define more than one uvs for vertex:
vertex ( x x x x x vertex_uvs ( num_uvs uv1 uv2 ...) )