Thomas, Thomas Schmidt wrote: > 2D/3D: It's own. Obviously. > 2D/ limited 3D : DXF > 3D import: BRep (OpenCascade), STEP, IGES [SNIP] Does my memory serve me correctly in thinking that your underlying kernel is the OpenCascade kernel? If so, what do you think of it? Have you ever done work with other kernels and if so how do you think OpenCascade compares? I'm thinking of using the OpenCascade kernel in a project aimed at the structural engineering market and am interested in comments from people who have used it. Regards, Andrew Lowe