[ODE] new ODE collision

[Erwin de Vries]

> On Sun, 10 Nov 2002, Russ Smith wrote:
>
> > > - When adding the ray class we should think about what the
> > > 'penetration depth' should be. Do you have any thoughts on this?
> >
> > i'm not sure that dRay will ever be attached to a body, in which case
> > penetration depth does not have much use for the dynamics. perhaps you
> > can think of a non-dynamics use/definition for the penetration depth?
>
> The first thing that came to my mind when I heard about the ray class was
> sensors for the critters I'm making in Juice, sort of like IR or
> ultrasonic rangefinders in robots, or like whiskers on cats.  I'd want to
> know the distance from the ray's origin to the first object it collides
> with.

Thats also what i'm thinking of. Its not what it currently does, but i
believe this would be more useful than the current version.

> Second, I think they might be useful for fast-moving objects - if you
> project a ray forward along a missile's direction of travel, you could get
> "collision" info in cases where the missile would otherwise teleport
> around an object due to its position changing by a distance greater than
> its length.  In that case, could the ray intersection be used to generate
> a contact joint, to stop the missile from penetrating?

I'd say it would be more appropriate to use a ccylinder here. Unless you
want it to bounce off of course.

Erwin