Each animation layer has a Weight value that determines how much of its animation plays in the result animation.

When the Weight value is set to 1, all of the layer’s animation plays in the result. A Weight value of 0 means none of the layer’s animation plays in the result.

As the result animation is calculated, the attributes of the animation layer are multiplied by the layer’s Weight value. For example, if you animate the translateY value for a bouncing ball on AnimLayer1, then decrease the Weight value to 0.5, the ball only bounces half as high when you playback the animation of AnimLayer1.

If you are working with a layer in Override-Passthrough mode, the Weight value also lets you control the opacity of the Override layer. See Override-Passthrough mode.

See also Keyframe the weight of animation layers.