[ODE] Geomgroups vs composite

[Adam D. Moss]

skjold@cistron.nl wrote:
> This does leave me wondering, is it still worthwhile to put the geoms from a single composite object into their own SimpleSpace?

I think so.  I don't see how ODE could reasonably be ahead
of you on this point because I don't think it would stoop
to caching the uber-aabb for the body's geoms on the body
itself (being the only common place to logically store it),
since the aabb is collision business and bodies are just for
simulation purposes.

Thinking about it, it might actually make sense for ODE to
keep an implicit SimpleSpace on each body for the geoms
attached to it, if there wasn't an effort to keep simulation
and collision distinct.  Also a lot of ODE seems to me to still
be oriented around making life easy in the case where
each body just has a single geom centred on it, with some
quite large hoop-jumping needed for the more complex cases
(geometry transforms, the centre-of-mass bug, and having to
explicitly put a body's geoms into a space if you wish to benefit
from an aggregate bounding box).

> I wouldn't mind being able to set user data on spaces

I haven't tried it, but since IIRC a Space just a subclass
of a Geom, you should be able to just use dGeom{S,G}etData

> Russel, and the other contributers too, great job!

Agreed.

-- 
Adam D. Moss   . ,,^^   adam@gimp.org   http://www.foxbox.org/   co:3
busting makes me feel good
'"Wankbadger" failed to reach MPs.  "Wank-badger" succeeded.'