I finally managed to to a projection of a certain planar-wire onto a topological surface. The wire that emerges from that projection is obviously not planar for all cases. Now my goal is to achieve a extrusion (TopoDS_Shape) of this wire with a certain direction an the same length of the extrusion vector for each point of the wire. I could walk through all vertices and calculate the faces, but is there another way with better performance and error checking?
BTW: It would be very helpful to upload a document in this forum!