[ODE] GIMPACT with doubles

Martijn Buijs buijs512 at planet.nl
Thu Nov 2 08:02:04 MST 2006


Jason Perkins wrote:
> On 11/2/06, Pierre Terdiman <pierre.terdiman at novodex.com> wrote:
>> Note that the only place where doubles are actually needed is the
>> world-space position of your objects.
> 
> I've wondered about this myself - why does /everything/ have to be in
> double precision? Do I really need that extra precision in the lengths
> of my box sides? Does it really help in the quaternions? It seems like
> we could save a lot of memory by only using doubles where they
> actually bought us something. It would be a straightforward -- if
> labor intensive -- modification.
> 
> Jason

Some time ago someone mentioned the way OpenGL does that. E.g. glTranslatef vs. glTranslated. 
Precision would be selected on a per API function basis. I'm not sure what the exact idea was (and 
how ODE would store stuff internally), but I remember some parts of the concept seemed to make sense 
and applicable to ODE. It is in the archive somewhere...

Martijn


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