[sldev] Body motion and facial expression tracking, Microsoft did it

[Jan Ciger]

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Argent Stonecutter wrote:
> I don't think it would be anywhere near so hard as getting a reliable  
> animation overrider to work in the first place. :)
> 
> Have you looked at the source for Franimation/ZHAO? Oh, there's a  
> certain amount of gratuitous yak-shaving in the code, but there's all  
> KINDS of special cases... and even then I'm always tinkering with my  
> copy to try and stop things like the skipping-up-steps effect.

You are missing a crucial difference - an AO merely plays "pre-cooked"
animations, turning off one and turning on another one. That is the
trivial part. The script only triggers them. The special cases are due
to the fact that an AO is a gross hack working around the fact that
there is no way to tell SL to play different animations instead of the
default ones.

Generating a procedural animation, be it IK, simple reaching anim or
walkcycle is several orders of magnitude more difficult - you have to
actually control the whole thing and calculate positions/orientations of
every joint and blend it properly. And you are likely doing this on the
server, because otherwise you wouldn't be able to synchronize two avatars.

Of course, from the script's point of view, it would be all black box.
However, tweaking the inputs, e.g. for IK, is far from trivial,
requiring deep understanding of how the skeleton works and the math
behind. How many scripters actually understand the concept behind the
rotation type (quaternion) and hierarchical transformations that are the
basic element of this? Here you will be giving the scripters another
black magic tool like that, probably even more complex. I doubt that
many people would be capable of using it effectively.

Regards,

Jan



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