[ODE] ODE Physics Benchmark Setup

[Jon Watte (ODE)]

WorldStep is more accurate, but takes longer on large simulations. 
That's "just the way it is."
Speed or accuracy, choose one :-)
The documentation talks about how to raise the number of iterations, but 
the problem is that accuracy doesn't go up enough with number of 
iterations, so QuickStep will still be pretty inaccurate.
Of course, that's just the solver -- then there's the design decision 
that ODE uses a first-order Euler integrator. It's designed for games, 
not for serious mechanical engineering.

Cheers,

          / h+


Bill Sellers wrote:
> That's interesting. My tests with QuickStep showed it to be  
> noticeably less accurate than WorldStep but I didn't know that you  
> could play around with the number of iterations. Any suggestions what  
> values to try?
>
> Cheers
> Bill
>
> On 26 Oct 2007, at 10:30, cris at cris.hspace.name wrote:
>
>   
>> Hi,
>> first of all, I think you shouldn't use the WorldStep. It's
>> the old "big matrix" solver, and this could explain why in
>> some of the tests the performance drop dramaticaly down!
>> (e.g. the stack test...). I believe that all the other
>> engines use some sort of "iterative" solver.
>> Secondly, for my experience the "best" setup is really hard
>> to be defined... it depends on many factors of the scene, of
>> course, but using the "QuickStep" (iterative solver) you
>> will notice difference in accuracy/performance playing
>> around with the number of iterations.
>> Cristian
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