Rhino 7 bug: deleting control pts in joined curves

This is a continuation of a thread in Serengeti:One end point of curve disappears when a particular middle-ish point is deleted

Rhino 7 has a significant bug. Delete the control point at the joint of a polycurve closest to the end of the polycurve and the control point at the end of the polycurve is also deleted. Attached file with several polycurves in blue and the same polycurves after control point deletion in green. Joints in the example are at cusps (G0 continuity).
Joinedcurvedeletebug11.3dm (1.6 MB)

Hi David - thanks, I’ll take a look - I imagine this is related to the keeping of sub-curve structures in polycurves, new in V7.


Thanks Pascal. I wouldn’t be surprised if it is related to the new feature in V7. My guess is a coding error rathet than a logic error. I assume it will be going on the heap with some urgency.

The bug also occurs with edit points. Delete the edit point at the joint in a polycurve closest to the end of the curve and the edit point at the end of the curve disappears.

The problem involves the end of the polycurve, not the start of the polycurve.

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Hi David - I have been unable to reproduce this so far in the latest here - I know Mikko worked on the polycurve-maintaining-structure stuff some more, so it may simply be fixed now - if I time allows I’ll go back to an older build and check, partly to test if I am doing the right thing to see the bug in the first place.


@pascal I’m using Rhino 7 SR0 2020-11-4 (Rhino 7 BETA, 7.0.20309.06003, Git hash:master @ 368ab021c8426434a95c36999f545f918e04df2c). I’m hoping it has been already fixed in a new build.

I updated the example file with markers of where the control points / edit points to be deleted are, and of which end of the polycurves are shortened. I also extracted the control polygons.
Joinedcurvedeletebug12.3dm (1.6 MB)


Hi David -
I followed a link here from the “divide and split” thread and tested that file that you attached. Just as Pascal, I’m unable to reproduce that issue here. I am now running 7.4 and I suspect that Pascale wasn’t running 7.0 at the time that he tested.
Can you still reproduce that issue?

@wim The problem appears to have vanished. Version 7 (7.3.21012.11001, 1/12/2021)