I’ve got a hull surface with a horizontal crease. Splitting or trimming the surface using a planar surface or line at exactly (= within document tolerance) fails. Using the command ‘Intersect’ reveals that a part of the expected intersection curve is missing.
Trimming or splitting using a cutting object that is slightly above or below succeeds.
I’ve prepared a file that I can send in a PM in order to check whether there is something broken in the surface or in Rhino…
Assuming I understand correctly, all you have to do is go to front view and select the 2 red lines and run the Trim command. Then pick the parts you want removed.
After that you can join all the surfaces and run the Cap command to make it a closed polysurface.
In V8, I can trim the two outside ends using the red lines from the Front view. Afterwards they can be joined and capped to form a closed volume.
However, this does not seem to work in Rhino 7 here, which looks like the version you are using. I will try and figure out why…
Edit - it looks like in V7, the intersection between a plane which represents the trimming line extruded from Front view and the revolved pointy surface does not cut all the way through the object - it stops just short of the point. That is why trim fails I guess. Looks like the problem has been fixed in V8.
Thank you both for your replies. It got sorted in the end. Multiple horizontal splits of the last (top) section combined with the vertical red line projected on the surfaces made split work. the very last section (fraction of a mm in height) was rendered by the surface from curves command.
