Mixers

Pro-Only: Animancer Lite allows you to try out this feature in the Unity Editor, but it will not be available in runtime builds unless you purchase Animancer Pro.

Mixers serve the same purpose as Mecanim Blend Trees; they allow you to blend multiple animations based on a parameter. For example, you might blend between Idle, Walk, and Run based on how fast you want the character to move (such as in proportion to how far the user tilts a joystick) so that they animate appropriately for any speed instead of only having a few specific speeds they can move at.

Blend Trees vs. Mixers

The Linear Blending example demonstrates how to use both Mixers and Blend Trees.

There are several key differences between them:

Blend Trees Mixers
Creation Manual in the Unity Editor. Dynamic at runtime.
Modification Can't be modified at runtime. Can be modified freely after creation.
Details You have no access to any of the internal details. You can directly access the details of individual states.
Synchronization Time and Foot Phase Synchronization, but it's always on for all states. Time synchronization only and you choose which states are synchronized.
Customization None. You can create your own mixer types that inherit from any of the existing ones to implement custom blending algorithms or add other features.

Also note that Blend Trees can be played in Animancer using using Parameter Controller States.

Mixer Types

There are several different types of Mixers and you can create your own by inheriting from any of them:

Mixer Type Parameter / Thresholds Interpolation Algorithm Equivalent Blend Tree
ManualMixerState none Manual Weights Direct
LinearMixerState float Linear O(n) 1D
CartesianMixerState Vector2 Gradient Band O(n2) 2D Freeform Cartesian
DirectionalMixerState Vector2 Polar Gradient Band O(n2) 2D Freeform Directional

Manual Mixers

ManualMixerStates allow you to simply control the AnimancerNode.Weight of each state manually without any automated calculations. This is often useful for additive animations and blend shapes for things like facial expressions.

Parameters and Thresholds

Other Mixers have a Parameter property and Thresholds array which are used to calculate the weight of each state for you.

  • The Mixer Creation page explains how to set the Thresholds.
  • When the Parameter is exactly equal to a particular threshold, the corresponding state will be at exactly 1 weight.
  • Parameter values between the Thresholds will calculate fractional weights based on the interpolation algorithm being used.

2D Mixers and Dead Zones

When selecting a 2D mixer, Directional generally offers better interpolation than Cartesian for animations that represent direction such as move forward/back/left/right.

In areas with 180 degrees or more between states the interpolation is ill-defined and will likely have undesirable results. For example, if you have clips for forward, back, and left, but no right, then you will get odd results if you set the parameter to the right.

Other Details

MixerStates are a type of AnimancerState with several other differences from regular ClipStates:

  • The Clip property will always return null.
  • Length, Time, and NormalizedTime are calculated using the weighted average of the Mixer's children.
  • You can access the children of a Mixer via mixer.GetChild(x) or mixer.ChildStates[x].
  • The children aren't given a Key (unless you manually set it).

Events

There are several important things to note when using Events with Mixers:

  • Animancer Events can be assigned to a Mixer or its child animations:
    • Events on the Mixer will trigger based on the weighted average NormalizedTime of all children.
    • Events on a child will trigger based on the NormalizedTime of that specific child.
  • The Inspector for a Mixer Transition only allows you to configure events for the Mixer itself, but if you assign a Transition Asset as one of its animations then that asset can define the events for that animation.
  • While a Mixer is playing, events for all of its children will be triggered at the appropriate times, even those with no Weight. If you want to avoid this, you can access the AnimancerEvent.CurrentState during an event callback to check if the event should actually do anything.
  • Animation Events work the same as Animancer Events registered on the Mixer's children.
Mixer Creation There are a few different ways you can create a Mixer.
Mixer Smoothing Smoothly change the parameter of a Mixer over time.
Mixer Synchronization Mixers can synchronize the timings of their animations.