Okay, not sure if anyone has come across this but: mesh.SetIndices(quads, MeshTopology.Quads, 0); Results in the mesh being created with double quads by the looks of it, so rather than creating 2 triangles per quad, it creates 4 triangles per quad, the original 2 you'd normally get plus another 2 rotated 90 degrees with flipped normals!! Anyone know of a workaround? This only affects PSM (I've built the same game on Windows Phone, BB10, iOS and Android) Thanks, Jon