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Unity Knowledge Required

This document is written with the assumption that you know a bit about Unity Animators.

This is a list of Parameters (case-sensitive) that can be added to any Playable Layer (animation controller) and change across all Playable Layers that include this parameter. User created parameters that are not in this list will exist only locally within that animation controller and are not currently changeable by the avatar.

You'll need to add these to your Playable Layer animators to use them. They are case-sensitive!

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Don't Dead-End!

You should assume that parameter values may change. If you "dead-end" your animators-- as in, you don't have an "exit" in any particular branch-- you may end up having a broken avatar.

Parameters

"Supine" and "GroundProximity" are visible in the Debug display, but are not implemented yet. They currently do nothing and never change values.

† GestureLeftWeight and GestureRightWeight go from 0.0 to 1.0 in various gestures depending on the trigger pull. For example, if you make a fist but don't pull the trigger on the left hand, GestureLeft will be 1, but GestureLeftWeight will be 0.0. When you start pulling the trigger, it will climb from 0.0 towards 1.0. This can be used to create "analog" gestures or conditionally detect various things.

Parameter Types

You have access to three types of variable when defining your parameters in your Parameters object.

You can use up to a total of 128 bits of "memory". This isn't strictly memory in the sense of memory usage of the avatar, but has to do with the bandwidth you use when syncing parameters.

GestureLeft and GestureRight Values

GestureLeft and GestureRight use these as their values:

Viseme Values

We use the Oculus viseme index, top to bottom, where sil is 0. For reference:

Sync Types

• Speech - Only used for visemes, is driven by the Oculus Lipsync output parameters depending on your speech. Updated locally, not directly synced (because its driven by audio)
• Playable - A slower sync meant to synchronize longer-running animation states. Updates every 0.2 to 1 seconds, but you shouldn't rely on it for fast sync.
• IK - Syncs much faster, with the exact same frequency as Networked IK. Depending on the parameter, this may also just be calculated based on the avatar's locally rendered IK state.

When a Expression parameter is in-use in a Puppet menu, it automatically swaps from Playable to IK sync so you get the faster sync.

Driving Expression Parameters

In addition, Expression parameters can be "driven" to a value via State Behaviors. They can be set using the Avatar Parameter Driver State Behavior on a state in an animator.

AFK State

The AFK state is triggered by:

• The user removing the headset and the HMD proximity sensor returning that the headset is not being worn
• A system menu is open. This depends on how the platform you're using delivers data when system menus are up-- for example, the Oculus Dash doesn't register as AFK, but SteamVR's menu does register as AFK. This is kind of a knock-on, and not a designed behavior.
• The user has pressed the End key, toggling the AFK state.

TrackingType Parameter

TrackingType indicates a few pieces of information.

If the value is 3, 4, or 6 while VRMode is 1, the value is indicating how many tracked points the wearer of the avatar has enabled and currently tracked. This value can change! If a user in 6-point tracking removes their extra three points of tracking, they will go from a value of 6 to a value of 3. Take this into account when you design your animator.

If the value is 0, 1, or 2 while VRMode is 1, the value indicates that the avatar is still initializing. You should not design animators to branch based off this combination of values, and it should instead wait for a "valid" value of 3, 4, or 6.

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Account for Changes

During avatar initialization, this value may change! Ensure that your animator accounts for possible changes, and that it doesn't "dead-end" into any branch.

Expression Parameter Aliasing

You must create names (or "aliases") for Expression parameters. You cannot (and shouldn't!) use the default ExpressionN name for the parameters.

Once you have created names for any Expression parameter you want to use, you can use that name directly in your Controller. This means can come up with your own standard naming for your parameters. This also means that Menu definitions and Controllers can be mixed and matched as long as they use the same names. You can get prefab controllers from others and create your own menu styles based on your preferences, without worrying about Expression parameter conflicts.

Default AV3 Aliasing

There's a few "defaults" in use by the template AV3 VRChat controllers that you can use if you don't want to build out your own controllers. These won't collide with your own use (as long as you don't name them the same thing) thanks to aliasing.

In particular, the Default Action and FX layers use aliasing. You don't need to worry about using a Expression that is in these layers.

Actions use aliased parameters named VRCEmote , which is an Int with a range of 1 to 16.

FX uses aliased Float parameters called VRCFaceBlendH (-1,1) and VRCFaceBlendV (-1,1), if you want to try out your own menus to use them. The default FX layer requires that you have a skinned mesh named Body with mood_happy , mood_sad , mood_suprised , and mood_angry blendshapes.

To restate, if you have an avatar that you upload as an Avatar3 avatar without any custom Playable layers, you'll be able to use some built-in emotes with them as long as you've got the above-named blendshapes.

If you also have an eyes_closed blendshape, it'll close them when you use the default Die emote or go AFK.