2009

Linking the Center of Mass Object
Using the
Select And Link tool on page 3343 you can link the center of mass
object to another object if you need to reposition an animation sequence. An
example of this might be a surfer. You could create an animation of a biped
running up and down the surfboard, hanging its toes off the end of the
surfboard, and so on, and then link the center of mass object to the board.
When you animate the surfboard, the biped animation would travel with it.
The biped moves with the surfboard because the center of mass is linked to the
surfboard.
Because the COM is the root object in the biped hierarchy, it is the only object
in the biped that you can link directly to other objects in the scene by using
Select And Link. To make other body parts, such as feet and hands, follow
other objects in the scene, use the technique of IK attachment: see
Animating
IK Attachments
on page 4278.
Center of Mass Shadow
The center of mass shadow object, the circle between the biped’s feet on the
world plane, provides a sense of the position of the character’s center of mass,
relative to the feet. Another use of the center of mass shadow is to link objects
Biped User Interface | 4327