[ODE] Geom Transforms hate me

[Russ Smith]

> If it's any help, I looked at this myself several months ago and
> concluded that the mass offset adjustment for composite objects
> in test_boxstack probably wasn't doing the right thing anyway

do you know what the bug is? i observed some slightly odd behavior with
the composite objects in this demo, but i didn't have time to chase it
down.

the fact that geometry and mass are completely independent things in ODE
certainly makes it annoying to create composites. what the boxstack demo
is doing IIRC is (1) computing the total mass and inertia of the composite
object by summing up the pieces, (2) finding the offset of the body center
of mass to the composite object center of mass, (3) offsetting
the geometry and body positions so that the body center of mass is equal
to the body point of reference. this last step is needed because ODE
bodies *must* have center-of-mass == point-of-reference.

russ.

--
Russ Smith
http://www.q12.org/

--
On Thu, 25 Sep 2003, Adam D. Moss wrote:

> Panayoti wrote:
> > I understand what mass translate does, I'm just not exactly sure what
> > the code in the ODE tests is doing.
>
> If it's any help, I looked at this myself several months ago and
> concluded that the mass offset adjustment for composite objects
> in test_boxstack probably wasn't doing the right thing anyway
> (just in case this is what you're studying as a template).
>
> --Adam
> --
> Adam D. Moss   . ,,^^   adam at gimp.org   http://www.foxbox.org/   co:3
>
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