[ODE] Euler vs. Runge-Kutta and adaptive step sizes

[Adam Moravanszky]

> I believe the difficult part of non-Euler integration is the fact that
> ODE uses Stewart/Trinkle's time-stepping algorithm, where the numerical

I don't believe ODE is based on Stewart and Trinkle's time stepping
algorithm, as described in the paper "An Implicit Time Stepping Scheme for
Rigid Body Dynamics with Inelastic Collisions and Coulomb friction" because
this paper uses position based inequality constraints, while ODE uses
velocity inequality constraints, among other differences.  This basic
assumption leads to a totally different problem that has to be solved, which
is an NCP in the S+T paper.

Of course, maybe there are newer results I am not aware of?

I agree with you that ODE's LCP solver is also integrated with its
integrator to some degree, but this dependency can be easily removed (though
I would not encourage doing that).

--
-- Adam Moravanszky
http://n.ethz.ch/student/adammo/