2009

Bones That Compress
One way to use bones with the biped is to use the Select and Link tool
on the 3ds Max toolbar to link the root of the bone to one part of the biped
and have the bone End Effector follow another part of the biped. As the biped
moves these bones compress and expand.
In the image of the mechanical leg, piston objects are linked to the bones. As
the bones compress and expand, they also animate the linked piston assembly.
As the bones compress and expand in the abdominal area in the bottom image,
the envelopes created by Physique for the bones compress and expand to
animate this area on the mesh.
IK Solution
In the IK Controller Parameters rollout, you specify the accuracy of the IK
solution and the frame duration of the solution. For bones that compress, you
generally want an accurate solution to ensure that the bone follows the end
effector perfectly, without any drift. In the image of the rollout Position has
a value of 0, the least amount of allowable distance (Rotation is at its default
value of 1, the Rotation End Effector is not used in this example). Iterations
is set high, ensuring that that the solution is accurate, even if the character is
scaled down a great deal. Start and End Time should span the animation.
There are many ways to use bones with the biped. You could automatically
animate the bending of a hose that is attached to a character’s shoulder and
mouth when the biped head rotates, for example. Bones attached to the biped
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