[ODE] Convex Geometry

[Harald Schmid]

Surprisingly, one contact point is enough for our application. I
actually thought that this would be the major obstacle, however it is
not.

Here's my interpretation: If two objects collide, that will take place
over 1/10 of a second. Since collision detection runs 500 cycles per
second, I get 50 penetration depth vectors. That's a lot of
information to work with.

But that's only guessing. Fact is, collision detection and handling works well.

Harald



On 4/13/05, Pierre Renaux <prenaux at alias25.org> wrote:
> Hi,
> 
> If you got only a penetration depth how to you convert that to the
> several contact points required by ODE ? Or is that enought to convert
> to one contact point ?
> 
> - Pierre
> 
> >I have combined ODE with SOLID, which uses GJK. It works perfectly
> >well, although I have only the pentration depth to work with.
> >
> >A convex object is a convex set. And a convex set is defined as
> >
> >B is a convex set <=> for every x,y in B and any s in [0,1] it is true
> >that z = s*x + (1-s)*y is in B.
> >
> >Or in words: A set is convex if for any two points in the set the line
> >connecting the two points is also contained in the set.
> >
> >I don't know if there is such a thing as a concave set.
> >
> >Harald
> >
> >On Apr 12, 2005 7:24 PM, Jeffrey Smith <jeffreys at softimage.com> wrote:
> >
> >
> >>Stephen say wrote:
> >>
> >>
> >>>Just wondering if anyone has ever experiemented using a trimesh to simulate
> >>>a convex geometry (like a bucket for example).
> >>>
> >>>
> >>A bucket is actually conCAVE. Convex objects are locally spherical everywhere
> >>(i.e. no cavities, dips or valleys).
> >>
> >>But to answer your question, trimesh vs. primitive collisions are relatively stable,
> >>but trimesh/trimesh collisions remain problematic.  An implementation of GJK/EPA
> >>would fit well into ODE, if you're looking for a "fun" project.
> >>
> >>-jeff
> >>
> >>_______________________________________________
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> >>http://q12.org/mailman/listinfo/ode
> >>
> >>
> >>
> >
> >
> >
> >
> 
> 


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Harald Schmid
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