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Convex hull

Open angus-g opened this issue 9 years ago • 4 comments

I'm a fan of being able to generate a convex hull of multiple shapes. From what I can tell, this can't quite be replicated by CSG nodes at the moment.

angus-g avatar Jun 07 '15 08:06 angus-g

Discussed on the list. From @mkeeter:

Interesting question. There isn’t anything equivalent at the moment, because convex hulls fall into the category of “easy to do with b-reps, hard to do with implicit surfaces”.

If anyone has thoughts (or relevant research literature), I’d be interested in thinking more about this kind of operator.

AstraLuma avatar Jun 07 '15 11:06 AstraLuma

Perhaps the developers of Openscad might give a hint on how to do it?

Pupo1 avatar Nov 12 '15 05:11 Pupo1

The internal representation used by Antimony (functional representation) makes this non-trivial, as discussed in #31.

tl;dr: Antimony doesn't actually know the shape of a model, it knows a function that happens to be at 0 in all the places the model is. This makes certain operations easier (CSG) and certain operations harder (offsets, hulls).

AstraLuma avatar Nov 12 '15 19:11 AstraLuma

Is it completely out of the question to introduce non-implicit surfaces for these kind of problems? Transform the functional representation into an SDF. SDF to convex hull is fairly straight forward.

aurelw avatar Oct 01 '16 11:10 aurelw