[ODE] Trimesh Temporal Coherence Patches

[Erwin de Vries]

> > It'll probably be the latter until someone can either show
> > where the cached data is re-validated as correct by the code that
> > uses it, or can submit a fix.  My concern is that the subtle,
> > intermittant and hard-to-reproduce wrongness that might occur due
> > to this minor foible of the TC implementation could cause ODE's
> > users a lot of pain to pinpoint.  I'd be happier knowing that I
> > was wrong or that there was a fix in-hand.
>
> It might be good to ask Erwin on why did TC appear in TriCollider (back in
> ODE 0.035 and Opcode 1.2 times there was no TC)... There might be good
> reasons for it :)

The reason is actually quite simple. Its faster in some cases of really deep
Opcode trees. I think i mentioned it being not optimal when i submitted the
code. I dont think it would ever result in a crash or wrong behavior
however. It would not crash because even if a pointer is reused it would
have to be the same type of object (sphere or box). It would not lead to
wrong behavior because the actual box would be compared to the cached box,
and if the cached box does not contain the current box the cache results are
flushed and refreshed.

I definately vote in favor of the enable/disable system.

Erwin