CAP 211 - Interactive Design and Game Development

Chapter 34 - Motion Mixer


This lesson discusses reusing saved animation clips. Objectives important to this lesson:

  1. Saving animation files
  2. Motion Mixer
  3. Editing clips
  4. Creating transitions
  5. Loading animation files
  6. Mapping objects
  7. Retargeting

The chapter begins with the idea that you can save animations that you may use again. You have probably seen many cartoons that seemed to use the same character movement over and over. This is one application of the concept.

  • biped animation - this type of animation can be saved in three file formats: .bip, .fig, or .stp. This lesson discusses the .bip (biped animation) format, which is the only one of the three that the Motion Mixer can use. Create one of these with the save button on the Biped rollout.
  • non-biped animation - this type can be saved as an .xaf (XML animation file). Create one of these from the File menu: File, Save Animation.

The Motion Mixer utility has an interface that is different from what you have seen in 3DS Max. It is a little like Flash or Adobe After Effects, in that it uses a timeline and layered tracks to create something from components.
Question 1: What are the two ways listed in the text to access the Motion Mixer interface?

The text, as it often does, describes in detail without any context: it tells us many things we can do but it does not tell us why to do them.

Animation clips are loaded into the mixer, and they appear as horizontal tracks. You can edit a clip by trimming material from either end. Just drag the end of the clip toward the middle.

Time warps affect the timing of a clip. Clips can be sped up or down with a time warp.

Tutorial Notes and Questions

Tutorial 1 (Mixing biped animations):

  1. In a new scene, create a biped as instructed.
  2. Make sure the biped is selected. Open the Motion panel. Click the Mixer button as instructed. Check to see that the Mixer mode button is automatically activated in the Biped rollout.
  3. Since you just made the biped, it has no animation yet. Follow the instructions to load the Walking.bip file. (You will find it in the folder for this chapter, not where 3DS Max looks by default.)
  4. Follow the instruction to add a new Layer track below the current track.
  5. Select the new layer track, and add the fighting stance.bip file to the track. (3DS Max should look in the right place this time, since it is in the same folder as the last file you opened.)
    Note that the two clips are of different lengths.
  6. Use the figure on page 827 as a guide to add the tracks as instructed.
  7. Watch the animation as instructed.

This is the only tutorial in this chapter. Its instructions do not quite work. Experiment with them to get the best result you can.