Switch to point control select mode

** Hello dear forum **

There is a way to select alternative control points uv on surfaces and curves.


Hi Vikthor - I did dig up an old script that might help - I don’t say this is the most refined thing - for whatever reason I did not really finish the ui and workflow part but it does seem to work- you tell Rhino what direction (U or V) and how many points to skip, then select a surface point and it will select the pattern of points. Use RunPythonScript to test, or macro with

! _-RunPythonScript "Full path to py file inside double quotes"

SelPtPatterm.py (4.4 KB)

@vikthor , I made a couple of changes and updated the script.

@Vanessa, I think you asked me about this recently as well but I’d forgot that I’d already written this thing .

One obvious improvement would be to keep the current selection when running this - I’ll see about that.


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How can I download a file correctly?

Hi Vikthor - you should be able to click on the file name in my post above and download.


@pascal does not work

What does not work, the script or the download? If the downloaded file has a stupid nonsense name (lately Discourse has been doing this) , then rename it to “SelPtPattern.py” after downloading. Right-click on the link and choose Save As… does that work?

@vikthor - here is a zipped version:
SelPtPatterm.zip (1.5 KB)


the download

@pascal Thank you

I do not know what I’m doing wrong; but it does not run properly
jack.3dm (405.3 KB)

Yeah… your surface is periodic and has a singularity , I suppose that one of those is the problem - I only tested on more standard surfaces - I’ll see if I can sort that out. Not sure.


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Thank you
in spheres also does not run, Flat surfaces only
and in curves does nothing “does not work”

Yep, spheres would have the same problems - if you cut off the very tip of your cone and ShrinkTrimmedSrf it should work in U for that surface, and for V you’ll need to MakeNonPeriodic first. I don’t know how hard it will be to handle these cases…


I do what he told me, but he makes a selection in spiral or random
and in the case of the curves?

Yeah, I see that spiral thing too now - probably because the surface is closed, so the start point is the end point of the same row, which makes a mess of keeping track of the point indices… I’ll just have to do more work on it…
BTW, I looked more closely at the surface and I see that the tip is open, so my comments about singularities above are not relevant, though I would not be at all surprised if that does also cause problems.

I do not know if this idea works

  1. select the first string, example command “SelU SelV”
  2. then turn off the dots alternating, depending on the point you select

@pascal Oh yes I did! Thanks!