RE: [Algorithms] GJK termination

[metanet s. <met...@ya...>]

hi,
your tutorials are helpful, however.. it seems that
you always end up with a vertex-edge contact (i.e a
single contact point).

do you have any suggestions for how to handle
edge-edge cases, where there are two contact points?
(i.e when there are two colinear edges on the convex
hull) 

i've tried "fixing" this in the MD-construction phase
(detecting parallel edges there and making a single MD
edge instead of two colinear ones), and in the
calculate-penetration phase, however none of the stuff
i've tried thus far has been as simple, nice, and
well-behaved as the vertex-edge stuff (which works
every time).

thanks,
raigan


--- Pau...@sc... wrote:
> On 12/04/2005 09:26:30 gdalgorithms-list-admin
> wrote: 
> 
> >Hello again,
> > 
> > could you please outline the algorithm to
> construct the minkowski sum of 
> two 2D 
> > polygons in linear time?
> 
> Sure, its outlined roughly here
> http://www.pfirth.co.uk/collision.html (at 
> the bottom of the page)...
> 
> It relies on having a constant cost support mapping.
> 
> In overview, for two polygons A and B:
> 
> step around edges of A
> {
>         finding supporting vertex in B of current
> edge, 
>         construct MD edge
> }
> 
> step around edges of B
> {
>         find supporting vertex in A of current edge,
>         construct MD edge
> }
> 
> done!
> 
> Cheers, Paul.
> 
>
**********************************************************************
> This email and any files transmitted with it are
> confidential and
> intended solely for the use of the individual or
> entity to whom they
> are addressed. If you have received this email in
> error please notify
> pos...@sc...
> 
> This footnote also confirms that this email message
> has been checked
> for all known viruses.
> 
>
**********************************************************************
> Sony Computer Entertainment Europe
> 
> 
> 
>
-------------------------------------------------------
> SF email is sponsored by - The IT Product Guide
> Read honest & candid reviews on hundreds of IT
> Products from real users.
> Discover which products truly live up to the hype.
> Start reading now.
>
http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
> _______________________________________________
> GDAlgorithms-list mailing list
> GDA...@li...
>
https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list
> Archives:
>
http://sourceforge.net/mailarchive/forum.php?forum_id=6188
> 

______________________________________________________________________ 
Post your free ad now! http://personals.yahoo.ca