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

[Argent Stonecutter]

On 2009-06-04, at 08:55, Jan Ciger wrote:
> Argent, read my comment to Tigro's mail. It wouldn't work. At least  
> not
> in a nice way. For reaching and grasping you need much more IK than  
> just
> the three arm joints and then you are hitting a severely
> under-constrained and computationally expensive problem.

That's why you don't try and solve it computationally. You don't  
replace normal animation, you use this for minor adjustments to the  
existing animation, and you limit the strength of the adjustment to  
small angles and specific joints.

So it's down to the person selecting the base animation and providing  
the strength and possibly range (either distance or angle).

> E.g. in one case I have seen the solver to keep the hands next to the
> avatar's waist but stick the waist forward to reach a goal.

Wouldn't happen, unless the person selected the waist as the joint  
that would move, and unless the waist was already close to the goal.

> IK is a nice tool, but extremely hard to use unless you have an  
> animator
> guiding it.

Which is the point.