Havok is the physics
engine that performs collision
calculations for SL
. It should not be confused with the rendering engine, which was developed in-house (propietary). Havok is created by Havok.com, Inc.
, and is licensed by Linden
Lab for use in SL.
Second Life currently uses Havok 1.8.3, which is no longer supported by Havok.com, Inc. The latest version of Havok is 4, released on July 11, 2006. The move to Havok 2.x was slated to occur in SL version SL 1.7
, unfortunately, it did not occur. Andrew Meadows, a.k.a Andrew Linden, wrote a fantastic article
discussing how Havok currently works in SL, and detailing how the upcoming migration to Havok 2.x will benefit us. Havok 2.x offers faster and more accurate physics, ultimately allowing for greater object
complexity and better sim
performance, though the immediate benefits may be minor.
Though Havok 2 does indeed support rag-doll physics
for simulating realistic-looking behavior of human bodies, Havok 1.x does as well, yet SL does not take advantage of it. Andrew Linden has stated that a post-Havok 2.x SL will not either, at least not without a significant rewrite of the avatar code
. Havok also supports destructable objects, but again, this is unlikely to be implemented into Second Life because of the prim
Havok is frequently misspelled as "Havoc".
In a recent public meeting, Andrew Linden admited that Havok 2 will not be in the initial SL 1.7 release. He went on to say that it will be added when it is ready. When ever that is, Havok 2 has been a promised imminent feature since October, 2003 (becoming the biggest inside joke in SL).
A public roadmap of LL's upgrade of the Havok engine has not yet been found.
09/28/07: NEWS ABOUT HAVOK!
Effectively yes, Linden Lab announced today that they deployed Havok 4 on the beta grid, and once it's stable, it will be activated on main grid!
Go see by yourself: Havok4 is here on the beta grid
The 0.01m minimum size of primitives is definitely due to the limitations of the physics engine rather than for being "too small to see". However, Havok-2 will not save the day -- Havok-2 still has the default 0.1 meter "collision tolerance" as Havok-1, which means the odds of smaller prims in the debut of H2 in SL is almost zero. Nevertheless, I expect that we will eventually be able to reduce the minimum size allowed for primitives.
(Andrew Linden, 8/17/05