Reducing Keys

When you Solve a dynamics simulation, Position and Rotation keys are generated at every frame of the specified range for every object affected in the simulation. Not only does this result in an excess of keys for later editing, but it can increase the size of the .max file tremendously. The following steps show how to reduce the number of keys by using the Track View.

To reduce the keys generated by the Dynamics Utility, do this:

1. After Solving the simulation, check the animation to make sure it’s what you want, and then save that version of the scene.
2. Deselect every object in the scene.
3. In the Objects in Simulation area of the Dynamics panel, click the Select Objects in Sim button.

All objects included in the simulation are selected.

4. Open a Track View window, and then set its filter to show Animated Tracks Only and Selected Objects Only.
5. Right-click over the top object in the hierarchy list, and choose Expand All.

The Track View now shows all tracks in the simulation that have keys.

6. Go to Edit Time display mode.
7. Select all of the tracks containing keys (or simply right-click over the hierarchy, and choose Select All).
8. Double-click within any of the selected tracks to select all keys in all tracks.
9. Click the Reduce Keys button, set the Threshold to what you want (or leave it at its default setting), and then click OK.

All selected keys are reduced.

10. Save the reduced version of the scene (either under a new name, or by replacing the original file).