<aside> 🚧 This is a work in progress.

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Important distinction between Transform and Muscle animations

• Transform animations are any animation that positions, rotates, or scales a transform component. Constraint animations are not transform animations.
• Muscle animations are any animation that changes the value of a muscle of a Humanoid animator. Float parameters of the animator (Animated Animator Parameters) are not muscles.

<aside> ⚠️ The behavior of these two entities is different, so whenever this page mentions “transforms”, it does not imply “muscles”.

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Avatar masks in VRChat

Avatar masks are used to filter in specific muscles and transforms within a layer that will be effectively applied to the avatar.

For example, if you have one animation file that animates the finger muscles of both hands, you can have two layers with two different avatar masks:

• The first layer has an avatar mask that filters in (allows) the left hand muscles only.
• The second layer has an avatar mask that filters in (allows) the right hand muscles only.

By putting the same animation into both layers, the first layer will only animate the left hand muscles, and the second layer will only animate the right hand muscles.

Should I bother with avatar masks

Playable layers that isn’t the FX playable layer

You should apply an avatar mask to the custom sub-layers that you create within any layer that isn’t the FX layer (such as Gesture, Action, and Locomotion playable layers).

The avatar mask should be defined to allow the relevant transforms and muscles that you wish to animate within this layer.

TODO: Base layer??????

Avatar masks in the FX playable layer matter

The FX layer is normally used to animate anything that isn’t a transform animation nor a muscle animation.

Despite this, the FX layer has a special interest with Avatar Masks: