Someone "in the know" who had either been to SL views or SLCC or both pointed out a while ago that the upcomming Physical Avatars are being developed based on or using a new 3rd party system known as Endorphin.
Sure enough: Here it is. Note the LL logo at the bottom of the page. While I balk a bit at the thought of yet another bunch of third party libraries in the party *coughHavok* *sneezeSpeedTree*, there's a free to download Learning Edition, meaning you can play with some of the toys ahead of time, albiet in a different and more complex form than what is likely to end up in SL itself. (If you're feeling really rich, the commercial version exports BVH and retails for a mere $9,450 or $995 for a student version. Right. Moving on.)
The only constraint on the learning edition is that you can't export files to usefull formats to use outside of the program, though you can export videos to show work off. Some other notes and tips:
- The link on thier page to the tutorial videos don't work, go here instead: http://www.naturalmotion.com/downloads.htm
- The bottom right corner of the screen are the playback controlls. Clicking on the Simulate button will start the physics simulation of the characters and and record the results with can be replayd with the Play button.
- The character is in full ragdoll mode, meaning it will collide with the floor and the rest of it will move when you move or rotate one body part. To lock down parts of the body and pose a specific area, right-click on a body part above it (it will turn grey). For example, if you want to move just the legs and not the torso then right click on the pelvis before moving them around. Right click again to unfreeze.
-I haven't figured out how to rig an imported SL model in the program, but soon...