[ODE] RE: velocity constraints vs. acceleration constraints

[Gary R. Van Sickle]

>    One place where I've seen something that works only on 
> position constraints is in this Gamasutra "Advanced Character 
> Physics" article 
> (http://www.gamasutra.com/resource_guide/20030121/jacobson_04.shtml),
> where the author just uses an iterative "relaxing"
> algorithm to reposition particles after doing a 
> non-constrained forward integration step.  I'm not sure how 
> physically realistic this is or how well it extends to rigid 
> bodies (they just use it for particle
> systems in the article, I believe).   But the
> advantage there is that you are always guaranteed to end up 
> in a configuration where all of the position constraints are 
> satisfied.
> 

Isn't there some way to combine accelleration, velocity, and position
constraints into a single "Grand Unified Constraint Theory"?  Would it make
any sense to do something like this

While(constraints are being violated)
{
	Solve for positional constraints;  // This eliminates things like
interpenetration causing huge restoration forces
	Solve for velocity constraints;
	Solve for acceleration constraints;
}

?

I apologize if this is wildy dumb; I'm tired, and the mathematic/algorithmic
part of my brain refuses to get involved in any of this.

-- 
Gary R. Van Sickle