Hi all,
I would like to modify the control points of a Nurbs surface, similar to what the TSplineSurface.MoveVertices node does for TS surfaces. Due to the lack of such a node, I currently have to get all control point positions, modify my wanted points, and then I have to rebuild a new surface with the changed points.
This comes with problems, namely that trimmed surfaces become untrimmed.
Is there a way to just modify control points, instead of having to rebuild the surface? Maybe a call from Python code, or such?
Thanks,
GG
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Do you have a Dynamo graph nurbs surface which illustrates the issue?
I can for sure provide one, but don’t go ahead, and give me a solution which works on this one simple surface, by getting the trim curve, and recreate the trim. 
the problem in question will involve dozens of trimmed surfaces. 
I want to move any CV of the give surface, without having to untrim/retrim. Btw, I have to go via the “import SAT” way here, to keep the script Alias independent.
Already annoying: the surface arrives in Dynamo as “surface”. When I make it Nurbs (which it is/was) via ToNurbsSurface to get its control points, the surface gets untrimmed.
modify-nurbs.dyn (8.0 KB)
trimmed_surface.sat (14.2 KB)
Thanks,
GG
I think that is what I was trying to understand - how are you building a trimmed nurbs surface in Dynamo’s geometry engine. Soon as we trim we see “Surface” which once converted to nurbs loses the trim… I’m afraid that if we can’t solve that the ability to move a point is a non-starter as you lose the trim before you extract the points. Will see what shows up in the file though.
FYI @Aparajit_Pratap this might involve some deeper geometry enablement.
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@Aparajit_Pratap could you please let me know if there is a way (maybe via using a Python script) to modify the CV of a surface (or Nurbs surface)?
Not doable via Python - would need to extract and rebuild and the trim, which as you noted isn’t ideal for a host of reasons.
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