[ODE] Slow performence in a given scene - optimizable, or "just how it is"?

[Megan Fox]

Meh, disregard that - too vague a question depending on too many
variables.  That said, I'd be curious to know what sorts of geom
counts and numbers of calls to the callback others are getting in
performence-friendly scenarios.

On 11/4/05, Megan Fox <shalinor at gmail.com> wrote:
> Hrm... surprising results - I'd always though the total number of
> calls was larger than the number that actually go through.
>
> Profiling says that, yes, in the "bad" collision case, the total
> number of calls to my collision callback more than double.  However,
> that's still only, in this case, 246 calls, as compared to 145 in the
> "better" case.  These numbers seem a lot smaller than what I thought
> it would take to bring the system down.
>
>
> Does this seem right?  Is 246 collision callback calls, with a
> stepsize of 0.016 and 5 quickstep iters, in a world with very, very
> few actual dynamics objects (9 physical bodies total) enough to bring
> the system down like this?  Or am I seeing a problem elsewhere?
>
> (this is on an Athlon 64 2800+ - and the bad case is enough to bring
> me down to unplayably jumpy FPS)
>
> On 11/3/05, Jon Watte (ODE) <hplus-ode at mindcontrol.org> wrote:
> >
> > My first instinct would be to bake the collision of all static things
> > into a single static mesh (or a few, block-sized, static meshes).
> >
> > Another thing you can do is to add profiling code to count how many
> > near-callbacks you get, and store information about what attempts to
> > collide with what, and plot that. That should show you some spikes.
> >
> > Characters and other complex systems should probably be in their own
> > spaces (spaces can be hierarchical), so that they can be quickly culled
> > when not colliding with other entities.
> >
> > Last, I would absolutely use a profiler to figure out where the most of
> > the time is being spent. That would also guide me into making whatever
> > optimizations necessary.
> >
> > Cheers,
> >
> >                        / h+
> >
> >
> > Megan Fox wrote:
> > > Alright, I'm coming up against a performence problem in a semi-dense
> > > scene.  Semi-dense because, while there are a lot of objects in the
> > > world, it really isn't all that "dense"... it's just a desert with
> > > rocks and a single building.  I'm trying to determine if this is
> > > expected/normal, or if I can bail myself out in some fashion.
> >
> >
>
>
> --
> -Megan Fox
> Lead Developer, Elium Project
> http://www.elium.tk
>


--
-Megan Fox
Lead Developer, Elium Project
http://www.elium.tk