CAP 203 - Computer Animation III

Chapter 31 - Using Animation Modifiers and Wiring Parameters


This lesson provides some new techniques for animating faces and soft objects. Objectives important to this lesson:

  1. Animation modifiers
  2. Multiple versions of objects
  3. Morpher
  4. Flex modifier
  5. PathDeform
  6. Wiring parameters

This chapter begins with some information we have not seen before. We are introduced to object modifiers that provide animation features.

The text descibes using the Morpher modifier to transform one shape into another. This is illustrated in the exercise in which the author has provided three versions of a character's head, each having a different facial expression. The Morpher is used to change the original object so that it looks like each of the others in sequence. Basic techniques:

  • Create several copies of an object, once for each keyframe in a sequence. Model the various versions of the object to match the look you want in their keyframes. Finally, use the Morpher modifier properties to set which target model the actual object will look like in each keyframe.
  • Note that the text warns us that this Modifier will only work with a series of objects that have the same number of vertices.
  • The copies of the object may be hidden in the scene once you are done modeling them. It is the working object that will be morphed to match them. Do NOT remove them from the scene.

Assignment: Morphing facial expressions

  1. Load the file spcified on page 723 in 3DS Max.
  2. Follow the instructions to morph the character head.

In the lesson about reactor, we learned that objects can be soft bodies or rigid bodies. This chapter introduces the Flex modifier, which gives soft body (like a plush doll) characteristics to an object. The Flex modifier has subobjects that you should be aware of:

  • center - defines the center of the flex effect, not the center of the object. Think of the center as a stationary point. Points on the surface farther from the center flex more.
  • edge vertices - controls the direction and falloff of the flex effect. Remember from the lighting lessons that falloff means the area in which the effect fades to nothing.
  • weights and springs - sets the apparent mass of the object, and the tendency to return to the rest position after being flexed

Assignment: Making a flag wave

  1. Load the file indicated on page 727. Note the objects used: a plane with a mesh modifier and a flex modifier, and a wind space warp.
  2. Carry out the steps, and experiment with the properties,
  3. Discuss the settings you find useful with other class members and determine settings for moderate and high wind simulation.

The text describes the PathDeform modifier and shows an example of its use, but a tutorial is not provided.

Assignment: Write your own

  1. Experiment with the PathDeform modifier as described on page 730.
  2. Write a short set of steps to explain using this modifier. It should be similar to other tutorials in the text.

The text describes Wiring Parameters on page 732. The concept is simple: we can connect (wire) two parameters in a scene together, which means that if we change the first one, the second will change automatically. The wiring can be set so that a change in either parameter flows to the other. or so that changes only flow one direction. In the illustration on page 733, the radius property of one sphere is wired to control the x-position property of another sphere. This would be useful for showing astronomy concepts, like the orbit of a sattelite being determined by the radius of a planet.

The next topic is Manipulator helpers. I note that a Google search on the topic did not return many useful hits. You use it to get a graphic controller for parameters in your scene.