Shrink trimmed srf problem

please advise me what I’m doing wrong with the shrink tool. I want to trim the surface and move the control points to the edge. I normally work in Alias where the Trim-convert function. I found a shrink in the rhino, but the points don’t shift completely. The problem is in the picture. What am I doing wrong? Is there any other way to achieve a similar result from the alias? Thanks for the help.

AFAIK in Rhino7 (WIP) this is properly done

Shrink in V6 keeps the underlying surface rectangular just as you’ve shown.
That’s what the tool is supposed to do.

@ivelin.peychev, It’s properly done now. In V7 there is (currently a test) tool that will refit a new untrimmed surface to a trimmed edge if conditions are right - this is not the same as shrinking the original surface.



The test tool in V7 WIP is currently TestRefitTrim. It should be noted that usually the new surface will not be exactly the same shape as the trimmed surface, particularly at the trimmed edge. Changing the ExtraKnotPerSpan option from zero will add control points and improve the fit. In general if a sufficient number of points are added the fit can be within a desired tolerance.

I expect that the Trim-Convert command in Alias also usually results in surfaces with changed shapes. It is inherent in how NURBS math works and not specific to particular codes.

Thanks for the info @pascal,

Do you know if this refit method is exposed to RhinoCommon?

Hello - I believe the plan is that it will be in RhnoCommon, but I do not know if it is there now.


in v6 there is also _TestSplitRefit

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Thanks alot guys, _TestSplitRefit is working perfectly, you solved me next problem! It help me a lot, I appreciate that.

then you can try with the @pascal plugin: