Re: [Algorithms] Kinematic Collision

[Pierre T. <pie...@gm...>]

> >Handling intersections in the initial state - or at least a separate query
> that determines

>whether a given starting position is valid - is fairly important for a lot
> of things you might

>do with the character.  In our games characters transition between
> collision states,

>change models, transition from AI to player control, get teleported, get in
> and out of

>vehicles, transition from animation control to physical control, etc.  Most
> of these are far

>easier to implement if you can test for a valid starting position.
>
> Yes, I agree with that. That's why we exposed a set of functions to test
exactly this (if a given position is valid), However it puts the power (or
the burden, depending on your point of view) in the hands of users: -they-
have to test for valid positions. At the time we felt that it was more
efficient than running the "useless" depenetration code automatically all
the time.

The only problem with PhysX is that the queries to test for valid positions
only return a boolean answer (position is valid or not). When it is not, the
depenetration vector is not provided. So it is not as useful as it could be.
(Boolean queries are a lot faster and often enough, so that was the reason
IIRC).

- Pierre