At the moment, the only way I know to do this is: var subGeometry:SubGeometry = new SubGeometry(); mesh.geometry.addSubGeometry(subGeometry);
// find which SubMesh has this SubGeometry var subMesh:SubMesh; for each (subMesh in mesh.subMeshes) { if (subMesh.subGeometry == subGeometry) { break; } } // assign proper material to this subMesh subMesh.material = your_material; There should be a slightly better interface coming to achieve this at some point. This isn't ideal, I know. -Dave