Scripting / SL External Communication

Craig Berry cberry at
Tue Jan 22 12:44:08 PST 2008

On Jan 22, 2008 11:23 AM, Mark Meijer <meijer78 at> wrote:

> lol :-) Cool. Isn't Havok supposed to support continuous collision
> detection, though? Or was that added only in Havok 4... or maybe Havok
> 5, wouldn't that be hilarious.

All versions of havok support continuous collision detection, but the
version SL currently uses is prone to a condition nicknamed "deep
think" when two physical objects collide:

To avoid disappearing down the deep-think rabbit hole, the Lindens
have coded in all kinds of special logic that heads off potential
collisions before they happen.  It appears this is typically done by
making the objects involved temporarily phantom.  That's why you'll
occasionally see objects passing right through each other, as my atoms
did when the collisions with the piston got frequent and energetic

Havok 4 has improved collision logic better suited to hard realtime
processing deadlines, so presumably most or all of these safeguards
will be removed when it is in use.

Craig Berry -
"So we struggle and we stagger, down the snakes and up the ladder, to
the tower where the blessed hours chime."
  - Leonard Cohen, "Closing Time"

More information about the secondlifescripters mailing list