3ds Max 2012 Bible - Kelly L. Murdock [371]
Mapping animated objects
Mapping files define a relationship between objects in the saved animation file and objects in the current Max file. These relationships allow the animation keys to be transferred from one scene object to another.
Using the Map Animation dialog box
The Map Animation dialog box, shown in Figure 35.7, includes several rollouts. The Motion Mapping Parameters rollout includes options for allowing Max to make its best guess at mapping objects. If the scenes are fairly similar, then this option may be just the ticket. The Exact Names, Closest Names, and Hierarchy buttons allow Max to attempt the mapping on its own. This works especially well on bipeds that use the default naming conventions. You also can select to have Max look at the various controllers that are used when trying to match up objects.
FIGURE 35.7
The Map Animation dialog box lets you map objects to receive animation.
The Filters section lets you filter out the tracks that you don't want to see. The Lock button applies the selected filters to both the Current and Incoming lists.
The Map Track to Track rollout consists of three lists. The left list contains all the tracks for the current scene objects, the middle list contains all the mapped tracks, and the right list contains all the tracks from the incoming animation file. Select tracks and click the button with the left-pointing arrow to add tracks to the Mapped list; click the other arrow button to remove them.
At the bottom of the Map Animation dialog box are buttons for saving the current mapping file.
Retargeting animations
The Retargeting rollout, shown in Figure 35.8, lets you specify how the scale changes between certain mapped objects. Scale values can be entered for the mapped nodes as Absolute or Derived Scale values for each axis. Derived scale values can be obtained from a specific origin object. After the settings are right, the Set button applies the scaling to the selected mapping.
FIGURE 35.8
Use the Retargeting rollout to specify how the scale changes between mapped objects.
Baking Animation Keys with the Point Cache Modifier
When you add keys to an object to control its animation using modifiers, the modifiers remain with the object and can be revisited and altered as needed. However, if you have multiple objects that follow the same set of keys, such as for a crowd scene, then including a set of modifiers for each object can increase the overhead many times over. A simple solution is to bake all the keys into the object, allowing all the keys to be pulled from an external file. This frees the resources required to animate multiple objects and makes the animated keys portable. The Point Cache modifier makes this possible.
You also can use the Point Cache modifier when playback in the viewport is too slow because Max needs to compute the vertex positions of a huge number of vertices. Reading their position from a separate file increases the playback speed. You also can use the file on a cloned object to control its motion at a different speed.
The Point Cache modifier records the movement of every vertex of an object to a file. Point Cache files have the .xml extension, but they can also be saved using the older .pc2 extension. To create a Point Cache file, click the New button and name a new file on the hard drive. Then set the range of the animation to capture and click the Record button. Once recorded, the total number of points along with the sample rate and range are displayed for the active cache.
Caution
Point Cache files can be loaded and used only on objects with the same number of vertices as the original used to record the file. •
If you select the Disable Modifiers Below option, then all modifiers below the Point Cache in the Modifier Stack are disabled. You