Re: [Algorithms] Kinematic Collision

[<chr...@pl...>]

Pierre Terdiman wrote:
> >The problem we've found with a single ray is unwelded geometry or cracks
> >in geometry - the ray can fit between them and not register a hit
>
> ...and I seem to remember a presentation from Christer about this
> problem, listing "using fat rays" as one way to solve the problem.
> But then again, what is a fat raycast if not a sweep test? :)

You don't need fat tests to solve the robustness problem. You can
do robust (standard) rays just fine as long as you do the testing
properly and adhere to some rules.

Proper testing involves sharing all computations that can be shared
between neighboring primitives. Adhering to some rules involves
not letting your test point go into the surface of the polygons
and making sure the geometry is well-formed (welded, properly
convex, etc).


Christer Ericson, Director of Tools and Technology
Sony Computer Entertainment, Santa Monica