Le vendredi 31 décembre 2010 14:35:28, Jacques Rebourcier a écrit : > Hi all, > > Nobody here ? Every one disconnected for christmas holliday season ? > > I am struggling with my simulation game. This is a marble racing game that > looks like ode-collision-8-terrain.py tutorial. > > Actually, if you toggle this turial in wireframe mode, you will see some of > my issues (let simulation lasts a while). > > 1) Slow : > The simulation is too slow, as in a planet with low gravity. I noticed ode > stepsize = soya round_duration. Effectively, reducing round_duration under > 0.005 is better but still not perfect (seems to be less stable). I suspect > that visting world during each round (begin, advance, and end) make a > latency between ode stepping, and so fluidity/realism of simulation is > bounded by this round visiting mechanism. Correct or not ? > > 2) Jiterring : > Looks like the ball is some time "bouncy and dancing", small pops with > small linear and angular velocity. Occurs at low energy (when balls are > very slow), and frequency of contact is very high. Seems quite random > (more "bouncy" when CFM is higher). > > 3) Violent popping : > Can occurs at medium-low energy, when rolling, receiving a very stong > vertical impulse (generally angular velocity is low). > Other case is terrain collision at medium-high energy when angle with > contact normal is in the midle (neither horizontal, nor vertical > collision). Tried to fix with "contact_max_correcting_velocity", but > doesn't work as I expected... > > 4) Falling : > Some time balls are falling (rare) with no apparent reason. > I noticed that when stepsize is longer and whith certain size ratio betwen > sphere and terrain surfaces, it is more frequent. > > => All these are show stopper for my game idea (except 1) that could be > Ok). I tried several stability tricks from ode documentation, some seems > to work a little, some time i didn't notice any effect (as if ode binding > was "silently" broken), but never achieved something really stable. > => I don't know how to debug/help, we are in Pyrex and ode binding black > magic. > => I suspect matrix random computation insatbility (error margin), or > Terrain Collider weird integration with ode that could be at the heart of > problem, but the code seems to complicated for me. > => Could someone help me ? > > Best Regards > Jacques > > _______________________________________________ > Soya-user mailing list > Soya-user@gna.org > https://mail.gna.org/listinfo/soya-user >
Noticed that some Null vector are "Nan" rather than "0.0" in Soya causing Ode to bug (add_froce, add torque). Then incresasing surface contact layer more (0.2) help greatly (but still some pb). _______________________________________________ Soya-user mailing list Soya-user@gna.org https://mail.gna.org/listinfo/soya-user
