Hi Wout, I create a simple 3D box, and use DxfReader, it read OK. but when use DxfWriter to save the file, it failed for a SAT error, as shown in the attached photo, the SAR number of the 3D solid throw exception. Any ideas how to read the 3D solid, get is geometry extents. Thanks! Cheers, -Robin

I really need some code + data. - Wout

Sure, will do, in middle of the work now, will get that to you tomorrow or so, Thanks Wout! Cheers, -Robin