The beauty of this approach is that the export function is no longer dependent on the processing renderer (as was the case with my povwriter library) however it is a pity that I needed to customise the code to match each library. A major advantage of this method, is that the mesh2 format is well matched to the PovRAY internals, so that rendering is quicker and much better than as a union of triangles (as is the case with my povwriter library). The advantage of my original povwriter library (like dxf export) was that it could be applied to virtually any 3D sketch.