Hey trot. So for the example I posted, I used another program I have which has an isect command that will generate a point for the intersection of a plane and the curve. If I had to do it in BobCad only, I would use your previously generated surfaces with the section planes and generate intersection curves, then BobCad has a "point-intersection" command, that will get you the same points, to use for the planar drawing... Let me know if that's not descriptive enough.