Trimmed surfaces behavior

Hi all,

I have a strange situation when I trim “together” one lofted surface with an extruded surface.
After trim, I cannot project curves onto the lofted surface anymore.
Also it appears as the lofted surface “pulls” the radiused part of my extruded surface so it is no longer vertical (direction of extrusion)
See enclosed file for better understanding of the situation.

Can anyone help me resolve this?

surfacetrim.3dm (3.7 MB)

Hi Havard - use the green curve to trim both surfaces - I think things work then. I’ll see if I can figure out why trimming the surfaces to each other makes a mess at the edges.

Hmm- actually, I cannot reproduce the messy polysurface here - trimming surface to surface, then Join, seems to be fine…


Pascal, thanks for your feedback.

Strange indeed!
When using the intersection curve as cutting curve, I also get correct result.
But I am also able to reproduce the faulty result, e.g. when first trim by use of the “bottom” curve used for making the extruded surface.
I don´t know if it is the mathematics of Rhino that plays a trick, but strange it is.