Physique and Free-Form Deformations (FFDs)

You can apply Physique to a Free-Form Deformation (FFD) space warp, which in turn can animate a mesh that is bound to the FFD. For example, you could use this technique to animate a credit card or a box of cereal.

Procedures

To apply Physique to an FFD to animate the entire mesh:

Place an FFD (Box) space warp around the mesh to deform.
The box should be large enough to encompass the mesh. The number of control points you use for the FFD can be fine-tuned later by going back down in the stack to the FFD to adjust the number of control points.
Select the FFD and apply the Physique modifier.
Click (Attach To Node), and then click the biped pelvis or the root node of your bone structure.
If necessary, select the FFD space warp and adjust the vertex assignments of the control points so they are assigned to the proper links.
This can be done in the same way as done using Physique with a mesh, only there are fewer assignments to deal with. Although fewer assignments provide smoother surface deformation with the FFD, control points and their link assignments must be thoughtfully placed.
Use (Bind To Space Warp) to bind the mesh to the FFD space warp.
Link the mesh to the biped pelvis, or the root node of the bone structure, so it follows the skeleton and FFD as they move around the scene.

To use an FFD to complement the effects of Physique on a portion of a character mesh:

TipYou can use this procedure to animate clothes or amorphous shapes.

Place an FFD (Box) space warp around the mesh to deform.
The box should be large enough to encompass the mesh. The number of control points you use for the FFD can be fine-tuned later by going back down in the stack to the FFD to adjust the number of control points.
Select the FFD and the mesh and apply a Physique modifier to both.
Click (Attach To Node) and in a viewport, click the biped pelvis.
Select the mesh only, and add a Mesh Select modifier to the mesh above Physique in the modifier stack.
NoteIf you are using a NURBS model, use the NSurf Sel modifier (rather than Mesh Select) to select sub-object control vertices that lie inside the FFD lattice.
Go to the Vertex sub-object level (or Control Vertex), and select the set of vertices (or CVs) that lie inside the FFD space warp you are using.
While in the Vertex sub-object level, bind the mesh to the FFD space warp. Now only the selected vertices or CVs will be affected by the FFD.
With the mesh selected, highlight the Physique level in the stack, and assign all vertices or CVs affected by the space warp as blue (rigid). These should be the same vertices or CVs selected in step 5, above.
Assign the rest of the vertices or CVs that fall outside the FFD as deformable, in the same way you normally assign vertices to links with Physique.
Select the FFD space warp. If necessary, adjust the vertex assignments of the control points so they are assigned to the proper links.
You do this in the same way as you do when using Physique with a mesh, except there are fewer assignments to deal with. Although fewer assignments provide smoother surface deformation with the FFD, control points and their link assignments must be thoughtfully placed.