Hello, is it possible to create non-planar or non-Euclidean clipping/section planes in Rhino?
No. We have that feature request on the list as RH-3952 and I’ve added your vote.
Asuni used to have a plugin: Dynamic display | Asuni
Not sure if it works in R7 and it’s viewport only, so no vector output, I think. Also, I think VisualARQ has something similar.