Wish: "Split and rebuild" tool

The idea is to be able to split a single curve into two curves with custom degree and number of control points, while keeping the general shape almost intact. Currently, the “Rebuild” tool of Rhino has plenty of shortcomings and performs especially bad with rebuilding curves into single-span degree 5 and 6 control points. I think that this is unacceptable in 2023, considering the fact that single-span degree 5 and 6 control points (both, surfaces and curves) is the best way to create clean and easy to edit models.

The cutting object in my example could be either some object (point, surface, curve, mesh polygon, SubD face) or manually added point on free location along the length of the input curve.

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Hi Bobi - for now, you can Rebuild with the SubCrv filter when selecting - start and stop the sub curves at the point.

! _SelNone _Rebuild SubCrv _Pause  _Pause _Pause  _SubCrv _Pause _Pause _Pause _Enter _SelLast

Delete Input is ignored however…


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Hi Pascal, this little trick helps to a certain degree, except that it relies on the current implementation of “Rebuild” which will heavily distort the output curves and won’t preserve the general structure of the original curve before the slitting.

Anyway, your macro is handy and I will surely use it in certain scenarios. Thanks! :slight_smile:

Lets hope that this could be made into a smarter and more predictable new tool in the future.

Well, if rebuild needs to do something different, that is a different story. Any tool that rebuilds is going to use the current implementation of Rebuild. Maybe I don’t get what the goal is.


Hi Pascal, the current implementation of “Rebuild” produces highly distorted, “zig-zag”-like output curves and surfaces, especially those with degree 5 and 6 control points. A fix to this behaviour was requested in numerous topics in the past. Here is an example.

Hi Bobi- yes, sure, understood - that is unrelated to the splitting trickery though.


That’s for sure. The request is for a new tool that combines splitting and a proper rebuild. :slight_smile: