[ODE] Performance question
STenyaK (Bruno Gonzalez)
stenyak at gmx.net
Thu Sep 14 18:15:03 MST 2006
On Fri, 15 Sep 2006 02:52:23 +0200, Jon Watte (ODE)
<hplus-ode at mindcontrol.org> wrote:
> Is this in release mode or debug mode?
> Are you using floats or doubles?
> How big is your step size?
Doesn't matter for this problem (the problem happens indepndently of step
size), but i'm currently running physics at 300Hz.
> Do you empty your contact joint group every step? (doesn't hurt to ask)
> On what kind of client hardware?
Amd Sempron 2Ghz + 512kb L2, 512megs of ram (no swapping is needed at any
time during simulation), on a gentoo linux 2.6.16 or so. No other apps are
taking the cpu. It's been reported to also happen in windowsXP + msvc, and
to also be solved by replacing all suspension physics with hinge2 joints.
> If you run a profiler on the program while it's getting 1-4 fps, where
> does it say you're spending your time?
Running a profiler takes too much cpu time (simulation can't run realtime,
so graphics are not rendered anymore, and there are more side effects), so
i profile the important parts myself, using SDL timers (which give a
precission of msecs). The slowdown is definitely due to ODE (which takes
up to 95% of total app time, but usually 40-50%), but the timing is too
little precise to know if the problem is collision detection or the solver
(i get an average of 50% time of the sum spent on each of them, so i dunno
what to think about it).
Site: http://1ksurvivor.homeip.net <1kSurvivor>
Mail: stenyak AT gmail DOT net
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