[ODE] Dealing with momentary time spikes in terms of physicsupdates?

Jon Watte hplus-ode at mindcontrol.org
Wed Feb 9 12:58:53 MST 2005


> I'm considering trying to implement a fixed framerate (so deltaTime
> spikes be damned, the entire engine only services so much of deltaTime
> per step anyways), but that seems like a horrible hack.  Is the proper
> solution to this to add physics prediction code?  Something else
> entirely?

Fixed step sizes are not a horrible hack, they are the only path 
to sanity. If you ever want to do network play, for example, you 
will find your life a lot simpler with a fixed step size. Recording 
and playback is another case where it's The Right Thing To Do.

In fact, in original Quake, there were some shelves that you could 
jump up to if you ran at a frame rate larger than X, where you 
wouldn't reach if your frame rate was too low; this was because of 
the varying behavior of first-order integrators with varying step 
sizes. Non-repeatable simulation == bad.

Cheers,

		/ h+




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