Physique and Free Form Deformations (FFDs)

Physique can be applied to a Free Form Deformation object (FFD), 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

  1. Place a 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.

  2. Select the FFD and apply the Physique modifier.

  3. Click Attach to Root and choose the biped pelvis or the root node of your bone structure.

  4. Select the FFD space warp and adjust the vertex assignments of the control points so they are assigned to the proper links if necessary. 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.

  5. Use Bind To Space Warp on the 3DS MAX toolbar to bind the mesh to the FFD space warp.

  6. Link the mesh to the biped pelvis, or 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

Note: Use this procedure to animate clothes or amorphous shapes.

  1. Place a 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.

  2. Select the FFD and the mesh and apply a Physique modifier to both.

  3. Click Attach to Root and choose the biped pelvis.

  4. Select the mesh only and add a Mesh Select modifier to the mesh, above Physique in the modifier stack.

  5. Go to Vertex sub-object level, and select the set of vertices that lay inside the FFD space warp you are using.

    Note: If you are using a NURBS model, you will want to use a NsurfSel modifier to select sub-object control points that lay inside the FFD lattice.

  6. While in 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.

  7. With the mesh selected, go down in the stack to the Physique level 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.

  8. 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.

  9. 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.

 

 

 


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