The blend mode of an animation layer affects how the animation contained in the layer is blended with animation in previous layers in the animation stack. There are three blend modes:

• Additive mode: The animation layer “adds” its animation to layers that precede it in the animation stack and that affect the same FBX properties.

  For example, if AnimLayerA and AnimLayerB both contain curve nodes that control the X translation of an FBX node, the resulting X translation is the sum of the X translation values from both layers.

• Override mode: The animation layer overrides the animation of any layer that contains curve nodes that control the same FBX properties and that precedes it in the animation stack.

  For example: AnimLayerA and AnimLayerB are both in Override mode. The X translation value for an FBX object on AnimLayerA is 10, and on AnimLayerB X translation has a value of 15. In the resulting animation, the FBX object will have a translateX value of 15.

• Override-Passthrough mode: If AnimLayerC is in Override mode, the layer is always completely opaque, blocking all animation from curve nodes in preceding layers that affect FBX properties that are also affected by AnimationLayer3. But when the layer is in Override-Passthrough mode, you control the opacity of the layer by animating its Weight value.