Wish: I'd like cage to work on surface points

Wish: I’d like cage to work on surface points.

Do you want the Cage command to create a cage around surface control points?

  • or -
    Do you want the CageEdit command to work directly on surface control points?
  • or -
    Do you want to something else?

I want the cage command to create a cage around surface control points.

Yeah, I think the same underlying problem as with FlowAlongSrf and History is probably the culprit -grips are not top level objects that can be tracked in the same way. I was trying to hack a way with an intermediate point cloud - it might work, but looks like it will be way too clunky to be useful.


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Pascal, how can your selection sets plugin keep track of sets of points, but Rhino history can’t?

heh… yeah… the script (and the new named selections in V7 I believe, @Trav, am I making things up? ) uses the ID of the parent object, the grip indices and holds onto that via user data. It does not track the grips as objects at all. I do not know, but I suspect the cage and flow stuff would need a significant amount of surgery to do that two stage thing and there is alost certainly a better way - like grips having Guids… or something.


Currently in Rhino grips do not have unique id’s only index numbers. Those index numbers can often change or be reassigned in a different order if the total count changes. This makes them hard, if not impossible to track throughout their life times. There’s a road map to make these objects have better tracking but it’s a long road ahead.

That’s unfortunate.

How does flowalongsrf work with points? I mean, it works once - no history - but it’s better than nothing. Can cage do that?

Hi Peter - Cage holds the original geometry in place for editing - every edit, the thing reverts to the original, behind the scenes, and deforms a copy to the new cage configuration and then replaces the last one. That way edits are not cumulative, if you see what I mean, in terms of densifying breps and approximations inevitable in the refitting. At any rate, since grips are not real objects or geometry in Rhino, the process cannot, if I understand things correctly, accommodate them.

Certainly from a user’s perspective it is a perfectly reasonable thing to want to do…


I sorta get it. Thanks.