Constant Key Reducer

Activate the Constant Key Reducer filter to remove redundant keys. Redundant keys are keys that have the same value, which are equivalent to flat horizontal interpolations on a curve. Redundant keys are often a result of a resampled FCurve before filtering.

Before:

Resampled FCurve before filtering

After:

Filtered FCurve with redundant keys removed (based on Threshold setting)

You can set specific thresholds for each type of transform. Translation Precision, Rotation Precision, Scaling Precision, and Other. Other includes transforms like Blend Shapes and custom attribute curves.

The default values are:

Values represent generic units. This is why you may need to modify threshold values in relation to the world scale of your scene, for example with very large or small scale scenes.

If you use this filter to eliminate noise, for example, from motion capture data, then you may need to modify values.

Setting	Description
Translation Precision	Threshold for translation curves in generic units.
Rotation Precision	Threshold for rotation curves in generic units.
Scaling Precision	Threshold for Scaling curves in generic units.
Other Precision	Threshold for other curves in generic units.
Auto tangents only	This option ensures that only “auto” key types are filtered. Otherwise, keys with interpolation values greater than a certain threshold may get deleted.

Note

The Maya FBX plug-in converts all animation keys to User, which is not an Autoauto tangent. To ensure that constant key reducing occurs, deactivate Auto Tangents Only in the Constant Key Reducer options.