To LUGNET HomepageTo LUGNET News HomepageTo LUGNET Guide Homepage
 Help on Searching
 
Post new message to lugnet.cad.devOpen lugnet.cad.dev in your NNTP NewsreaderTo LUGNET News Traffic PageSign In (Members)
 CAD / Development / 1245
1244  |  1246
Subject: 
Re: Dimensions of the parts
Newsgroups: 
lugnet.cad.dev
Date: 
Tue, 13 Apr 1999 18:18:56 GMT
Viewed: 
1580 times
  
Lars C. Hassing skrev i meddelandet
<57F1FE754246D211A98700805FB79145815508@aarhus>...
> Anders Isaksson wrote:
> > - Just don't include equality (=) in your collision test! (?)
> 
> This would be my bet too. Allow for a small margin/overlap
> caused by rounding errors.
> 
> Since you cannot tell anything about inside/outside of a part
> but only have a bunch of faces (triangles and quads), the idea
> of comparing every face in one part with every face in another
> part is very clever.



One could go further down the algorithmic lane, and construct a
'bounding box' or 'convex hull' to get some indication of
inside/outside. Not watertight though (think Lego trees :-)

It would be much faster if the BB or CH method works, as there are not
so many faces to compare (OTOH, creating the BB or CH takes time).

--
Anders Isaksson, Sweden
BlockCAD:  http://user.tninet.se/~hbh828t/proglego.htm
Gallery:   http://user.tninet.se/~hbh828t/gallery.htm



Message is in Reply To:
  RE: Dimensions of the parts
 
(...) This would be my bet too. Allow for a small margin/overlap caused by rounding errors. Since you cannot tell anything about inside/outside of a part but only have a bunch of faces (triangles and quads), the idea of comparing every face in one (...) (27 years ago, 13-Apr-99, to lugnet.cad.dev)

3 Messages in This Thread:


Entire Thread on One Page:
Nested:  All | Brief | Compact | Dots
Linear:  All | Brief | Compact
    

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