Isotrim is making extra surfaces that weren't there

[shackleton (Sir Ernest Shackleton)]

Hello sailor!

This is a recurrent issue in the forum, you might want to perform a quick search before posting next time.

@Michael_Pryor

All components which evaluate a surface work on a surface, not the trimmed representation of a surface. Trimmed surfaces are not really trimmed in a sense, Rhino uses trim data to hide parts of the surface from you. There is always an underlying surface which is what you are seeing. There is no way to give a trimmed surface a domain as it relies on NURBS and NURBS surfaces are 4 sided objects. Same will happen for other components that use surface evaluation.

https://www.rhino3d.com/download/rhino/5.0/Rhino5Level2Training/

Here’s the solution I came up with:
The main workarround is that you have to rebuild your surface, because Isotrim cannot operate with Trimmed Surfaces.

ISOTRIM PROBLEM.gh (24.9 KB)

If this solves your problem, please mark the reply as solution.

Best regards,
Sir Ernest Shackleton