Hi Marco, I guess that could be possible but it may be difficult because the way CVolume works is by generating a triangulated .obj file. Currently you can't export just one face object out of a larger brep to a file. I guess it could be possible to also separate the object into individual surfaces and export them to a temp file one by one but yeah that's likely to be very slow.

For v4 I can add some more methods like something on a face to calculate its surface area without having to save it to a file and read it back in again, that should work much better.

- Michael