Manual pinning would be extremely useful. One example that immediately comes to mind is that
Sister Mocap Test I did a while back. For the most part, the feet are sticking to the ground in this test but when Sister starts jumping forward, her feet slip several inches backwards on each jump. This occurs because the dual Kinect point cloud is pushing the legs backwards and there is nothing behind the legs to keep the feet in place.
To fix this problem, I used Motion Builder's feet pinning to keep the feet locked in place for a few frames for each jump.
It will be wonderful when the user can do the same thing directly inside of Mocap Studio.
Keep up the great work guys! :)
G.