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 CAD / Development / Organizations / LDraw / 1926
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Subject: 
Re: Parts as volumes (instead of surfaces)
Newsgroups: 
lugnet.cad.dev.org.ldraw
Date: 
Mon, 8 Apr 2002 17:02:48 GMT
Viewed: 
252 times
  
In lugnet.cad.dev.org.ldraw, Damien Guichard wrote:

Anyway, the remaining problem is that most (if not all, including Brick 2 x
4) ldraw parts are not convex but concave. Is there any simply mean to
extend BFC with metacommands that split ldraw parts in convex subpart? Does
the topic deserve the effort? Any interest at all? Just an idea to see what
reply.

Wow, good questions.  We know that some collision detection is already
practical - Eric Olsen demonstrated that over a year ago.  But
decomposing LDraw parts into convex objects, that would be a trick.
Each external box 5 (or pair of box 5's) would have to be split into 5
different subparts.

What about antistud tubes?  How could those be decomposed?

Steve



Message has 1 Reply:
  Re: Parts as volumes (instead of surfaces)
 
(...) Stud4 primitive could be convex-decomposed just as Ring4 primitive is today. More generally, just as any LDraw surface is convex-decomposed with just triangles and quads (3,4 points respectively), I guess any LDraw volume can be (...) (22 years ago, 9-Apr-02, to lugnet.cad.dev.org.ldraw)

Message is in Reply To:
  Parts as volumes (instead of surfaces)
 
It has been said that, with ldraw parts, we have the geometry of TLG bricks. This is rather optimistic. Because geometry would be CSG descriptions that allow much more (although slower) than quads and triangles. CSG descriptions allow part collision (...) (22 years ago, 6-Apr-02, to lugnet.cad.dev.org.ldraw)

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