Rebuild Rhino 5 vs 6

please advise me with the REBUILD function, I’m already desperate. I was very used to using it in Rhino 5 to simplify curves and surfaces almost constantly. I always set POINT COUNT: 2 and I was sure that a simple single-span curve would be created, the deviation of which I could easily control using the DEGREE size. I’ve always been sure that a single-span curve of quite small order will be created. I have now changed the version to Rhino 6 and REBUILD does not work as before. Maybe REBUILD in Rhino 6 just doesn’t understand, but I often have to set the POINT COUNT number higher than 2 and I always have to try different values ​​for both parameters and I don’t have such easy control over the output and I’m more subordinate to what REBUILD allows. Sometimes I can’t create a single-span object. I know I can use REBUILD CRV NON-UNIFORM, but I don’t work as easily as I did with the classic REBUILD in Rhino 5. I understand that I want stupidity, but there is some possibility to run an old Rebuild from Rhino 5 in Rhino 6. I don’t want to use the old software only for one function, because I think Rhino 6 brings a lot of benefits. Sorry if I want the impossible and I want stupidity. Thanks for the help or for the advice.

If you set the degree to the cp count - 1 then you always get a single span curve. This is a mathematical constraint. Or do I understand you wrong?

Once you have a single span curve you can also call the changedegree command to increase or decrease cp count on a single span geometry, without making it a multispan…

Thanks for the reply. Maybe I gave a bad example, I’m sorry. I have another one here. Before rebuilding I have polycurve in Rhino 5 I am able to simplify it by setting PointCount: 2 Degree: 3. In Rhino 6, nothing is created with the same settings. I would like you to try this example.

Hello - V6 should not allow a point count less than degree + 1 . I cannot get the setting you show on the right; if I ask for two points, the degree immediately goes to 1 as expected, and the point count always goes to degree + 1 at a minimum. In V5, you are not getting what the dialog shows, you are getting the minimum points for a degree 3 curve.

The V6 dialog now shows you what you can have, rather than accept settings that cannot work and give you something different. Does that make sense?


Maybe a good idea would be to add a checkbox which allows the user to always get a single span output and only make the pointcount/order tweakable. This would actually prevent the user to set two settings. The V5 tweak was a workaround, which does not work anymore, and which is the complain here. Wouldn’t that be easily fixable? Otherwise a quick script could solve it here…


You can execute this script in the Python Editor (or by _RunPythonScript

import rhinoscriptsyntax as rs

crvIds = rs.GetObjects("Please select curves", filter=4)
order = rs.GetInteger("Please set order",3,1,11)

for crvId in crvIds:

Hi Tom - That seems like a reasonable idea - a Single Span check box which would auto-adjust point count or degree, depending on which number you tweaked last. I expect if we did this we’d stick with ‘degree’ so as not to introduce a new variable to training and Help…

RH-58239 Rebuild Single span



Thank a lot, I will try it.