Reduce Keys

Command entry: Track View

In the Key window, highlight the keys to reduce.

Keys menu

Reduce Keys

Command entry: Track View

Curve Editor

In the Key window, highlight the keys to reduce.

Keys Toolbar

(Reduce Keys)

NoteThe Reduce Keys button shown here appears on the Keys Toolbar only in Curve Editor (Classic layout), but you can add it to a Dope Sheet toolbar with Customize User Interface.

Use Reduce Keys to decrease key density. Animating with inverse kinematics, or creating any complex animation, can result in many keys, which can make editing the animation difficult. In the case of applied inverse kinematics, 3ds Max generates a key on nearly every frame. Often, the same animation can be produced with fewer keys. Having fewer keys in a track makes it easier to change your animation.

Reduce Keys analyzes the pattern of keys in a block of time and creates a new pattern of fewer keys that produces nearly the same animation. You specify how closely the new animation matches the original.

Procedures

To reduce keys:

Select an animated object.
Right-click the object and choose Curve Editor or Dope Sheet from the quad menu.
In the Track View Hierarchy list, highlight the tracks whose keys you want to reduce. Reduce Keys works only on highlighted tracks.
Optionally, in the Key window, specify a time range within which to reduce keys, as follows: Highlight a key at either end of the range to reduce, or drag a selection rectangle around the keys you want to reduce. Alternatively, in Dope Sheet mode, highlight specific tracks and then use Select Time to designate a block of time within which to reduce keys. If no keys are highlighted in a highlighted track, Reduce Keys works on all keys in that track.
You can use any of the above methods to specify different ranges for different highlighted tracks.
From the Keys menu, choose Reduce Keys.
3ds Max opens the Reduce Keys dialog. This dialog has a single Threshold parameter.

Raising the Threshold setting will increase the number of keys that are reduced. The higher the threshold, the greater the reduction.
Click OK to reduce the keys.
Observe the results. If you are left with too few keys, press Ctrl+Z to undo, then lower the threshold and reduce the keys again. If too many keys remain, increase the threshold and reduce keys again.

Tip It can take experimentation to find the right Threshold value for your particular animation.

Interface

Reduce Keys

Displays the Reduce Keys dialog.

Threshold

Sets a threshold value. Higher values will result in fewer keys.

OK

Accepts the Threshold setting and reduces keys as follows:

Keys are reduced only in highlighted tracks.
If any of a track's keys are highlighted, reduction is performed only within the indicated range (that is, between the leftmost and rightmost highlighted key for each track). If no key is highlighted, reduction is performed on all keys in the track.