Untrim Surface/Brep at a particular Edge in RC

[Will_Wang]

maybe you can re-trim the ones you want to keep

How can Surface.Trim() keep original UV domains?

You need to do the following: extract the u- and/or v-isocurves that you want to use for trimming (or any other surface curve, does not need to be iso-curves) convert the surface to a Brep use BrepFace.Split(curves) to split the one face of the Brep choose which part to keep of the resulting Brep. https://developer.rhino3d.com/api/RhinoCommon/html/M_Rhino_Geometry_Surface_IsoCurve.htm https://developer.rhino3d.com/api/RhinoCommon/html/M_Rhino_Geometry_BrepFace_Split.htm