A suggestion: For those transitioning from Alias, ICEM, or Catia, it would be good if Rhino would offer a Knots display, not only a Greville points display (Edit Points), because one could see directly how many spans a curve has, and how these are distributed along the length of a curve, and one cou…

[image] encephalon: ConvertToBeziers Pause N Enter None Sellast -group temp enter Intersect None -selgroup temp enter delete Great work!

Much appreciated! At last we can see what we want to see when NURBS surface modelling. Goodbye Greville points. On a curve, the interior knots are shown with points. On a surface the real isocurves generate curves. Two things: How to switch points/curves off with a right click on the same button …

I do like the default density, especially in wireframe view where I can select the surface not clicking on the edge but by clicking on the isoparm (even if it’s not the ‘real isoparm’)

in the next WIP, I’ve added a test command TestShowKnots that might be helpful: [image]

Great, that’s the spirit, that would be ever so useful!

[image] Gijs de Zwart: in the next WIP, I’ve added a test command TestShowKnots that might be helpful: Looks good and much appreciated but there is a bug. Knots are shown on only one surface of a polysurface even when all surfaces are selected. [image] TestShowKnots Bug DC01.3dm (195.8 KB) …

@davidcockey yes I saw that, that’s an easy thing to fix I wonder about the usefulness of showing the points and the isocurves at the borders. Pascal mentioned me he would rather not see those (and not show any knot-isocurves that are outside of the surface trim. I might opt for a switch to toggle …

@Gijs I’d prefer the toggle between showing only the knot isocurves on the trimmed portion are desired, and showing the knot isocurves of the entire surface. I envision uses for both. Shwing the knots for the entire underlying surface is an easy way to see the extent, and shape of the underlying s…

next WIP will show a few more controls. You can now add polysurfaces as well. [image]

That’s the business! Would be great to have this in V8 already ; ) Showing the entire Us and Vs also for split/trimmed surfaces is great; very often users wonder why “the surface is bigger”, not seeing it by showing its CPs. Now we need proper history, where a curve/surface (child) aligned to two …

Rhino curve/surface anatomy

Rhino

brian (Brian Gillespie) January 21, 2026, 7:06pm 31

RH-91541 is fixed in Rhino WIP

Topic		Replies	Views
Isocurve display which highlights surface knot curves request Rhino windows	0	57	October 9, 2025
Visibility of knots in curves and knot isolines on surfaces Rhino windows	7	587	April 18, 2021
Automatic generation of knots & isocurves Rhino for Windows	6	948	February 10, 2015
Displaying Knots Rhino for Windows	27	5342	November 6, 2016
Isocurves Gone Serengeti (Rhino WIP) windows	16	869	May 17, 2023

Rhino curve/surface anatomy

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