[ODE] eliminating all state

Martin C. Martin martin at metahuman.org
Thu Nov 21 17:12:02 2002


So I'm evolving little virtual creatures with ODE, and after the evolution
is done, I take the best ones and "play them back" with graphics and
logging and other fun stuff.  What I'd really like is for the simulation
to go through exactly the same calculations with exactly the same roundoff
errors, but at the moment there are small differences that creep up over
time.  Russ, you mentioned that ODE uses the correction at one timestep to
estimate the size of the correction at the next timestep.  Is there any
way I can reset this between evaluations?  Is there anywhere else state is

For the curious: I'm currently using the debug build with -ffloat-store,
and using exactly the same executable in both cases, so it's guaranteed to
have exactly the same compiler options, etc...