[ODE] ODE with non-penetration constraint

[Bill Sellers]

> If you still want to know more about impulse-velocity based  
> simulation, go here to read a set of lecture notes from Prof Jeff  
> Trinkle. Note that he's the first (along with Prof David Stewart)  
> to proposed a feasible formulation that can deal with exact Coloumb  
> friction model. Note that ODE-style and most game oriented LCP  
> formulations do not follow Coloumb friction exactly.

Of course most material combinations don't follow the Coloumb  
friction model either...

Cheers
Bill