3ds Max 2012 Bible - Kelly L. Murdock [434]
• Joint Angle Deformer: Deforms the vertices around the joint between two bones where the skin can bunch up and cause problems. This deformer moves vertices on both the parent and child bones.
• Bulge Angle Deformer: Moves vertices away from the bone to simulate a bulging muscle. This deformer works only on the parent bone.
• Morph Angle Deformer: Can be used on vertices for both the parent and child bones to move the vertices to a morph position.
All deformers added to a skin object are listed in the Gizmo rollout. You can add deformers to and remove deformers from this list using the Add and Remove Gizmo buttons. You can also Copy and Paste the deformers to other sets of vertices. Before a deformer gizmo can be applied, you need to select vertices within the skin object. To select vertices, enable the Vertices check box of the Parameters rollout and drag over the vertices in the viewport to select the vertices.
The parameters for the deformer selected in the Gizmo rollout's list appear when the deformer is selected in the Deformer Parameters rollout. This rollout lists the Parent and Child bones for the selected vertices and the Angle between them. This rollout changes depending on the type of deformer selected.
For the Joint and Bulge Angle Deformers, a new rollout labeled Gizmo Parameters or Deformer Parameters appears. The Gizmo Parameters rollout includes buttons to edit the control Lattice and to edit the deformer Key Curves. The Edit Lattice button lets you move the lattice control points in the viewports. The Edit Angle Keys Curves opens a Graph window that displays the transformation curves for the deformation.
Using the Skin Wrap modifiers
If you've created a high-resolution model that you want to animate as a skin object, but the mesh is too complex to move around, then the Skin Wrap modifier might be just what you need. The Skin Wrap modifier may be applied to a high-resolution mesh, and with the Parameters rollout you can select a low-resolution control object. Any movements made by the low-resolution control object automatically are applied to high-resolution mesh.
Tip
Skin Wrap is also very useful for animating clothes on a character. •
The Skin Wrap modifier has two available Deformation Engines: Face Deformation and Vertex Deformation. Each vertex contained with the control object acts as a control vertex. The Vertex Deformation option moves the vertices closest to each control vertex when the control vertex is moved, and the Face Deformation option moves the faces that are closest.
For each deformation mode, you can set a Falloff value, which moves vertices farther from the moved control vertex to a lesser extent to ensure a smoother surface. For the Vertex Deformation mode, you can also set a Distance Influence value and Face Limit values to increase the extent of influence for a control vertex.
The Reset button can be used to reset the control object to the high-resolution mesh object. This is useful if you need to realign the control object to the Skin Wrap object. When you're finished animating the control object, the Convert to Skin button may be used to transfer the animation keys to the high-resolution objects.
The Advanced Parameters rollout includes a button for mirroring the selected vertices to the opposite side of the control object.
The Modifiers menu also includes a Skin Wrap Patch modifier, which works the same as the Skin Wrap modifier, but it allows the control object to be a patch.
Tutorial: Making a simple squirt bottle walk
Creating a bones structure and applying a Skin modifier works well for characters with structure, but to animate the motion of an amorphous object such as a squirt bottle, the Skin Wrap modifier works much better than bones.
To animate a squirt bottle object walking using the Skin Wrap modifier, follow these steps:
1. Open the Walking squirt bottle.max file from the Chap 40 directory on the CD.
This file includes a squirt bottle model with all its parts attached together. The file also includes a simple