To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.cad.dev.org.ldrawOpen lugnet.cad.dev.org.ldraw in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 CAD / Development / Organizations / LDraw / 1926
    Re: Parts as volumes (instead of surfaces) —Steve Bliss
   (...) 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) (...) (22 years ago, 8-Apr-02, to lugnet.cad.dev.org.ldraw)
   
        Re: Parts as volumes (instead of surfaces) —Damien Guichard
   (...) 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)
   
        Re: Parts as volumes (instead of surfaces) —Steve Bliss
   (...) So stud4 would be decomposed into 16 trapezoidal prisms? That sounds like a fair amount of mark up. (...) Nod, true. But I'd rather decompose a 1x1 brick into 6 volumes (4 walls, 1 top and the stud) than 46 (one volume for each surface (...) (22 years ago, 10-Apr-02, to lugnet.cad.dev.org.ldraw)
   
        Re: Parts as volumes (instead of surfaces) —Erik Olson
     (...) That was only bounding boxes (minus the studs). The piece in question was matched against all other pieces, any pieces in a line above or below were put into a list. In case one of them intersected the piece in question, a new place would be (...) (22 years ago, 10-Apr-02, to lugnet.cad.dev.org.ldraw)
   
        Re: Parts as volumes (instead of surfaces) —Damien Guichard
   (...) Well, I can have a twisted mind sometimes. I know these moments when the best idea today, will just be plain stupid tomorrow. Thanks to Eric Olson for more precision: he used bounding boxes, not collisions. Also I still think, whereas higher (...) (22 years ago, 10-Apr-02, to lugnet.cad.dev.org.ldraw)
   
        Re: Parts as volumes (instead of surfaces) —Steve Bliss
   (...) Maybe I'm missing a technical distinction, but it seems he used bounding boxes *for* collision detection, as opposed to using exact volumes. (...) True. My point was, marking up the LDraw part files for volume decomposition would either: a) Be (...) (22 years ago, 11-Apr-02, to lugnet.cad.dev.org.ldraw)
   
        Re: Parts as volumes (instead of surfaces) —Erik Olson
   (...) "marking up" would be better done by machine algorithm, and would encompass the Connection Point proposal at the same time. It would indeed yield a separate definition of the parts. A lot of high-end CAD programs read polygons (like we have) (...) (22 years ago, 11-Apr-02, to lugnet.cad.dev.org.ldraw)
 

©2005 LUGNET. All rights reserved. - hosted by steinbruch.info GbR