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Animator Parameters

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!

Don't Dead-End!

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

Parameters

NameDescriptionTypeSync
IsLocalTrue if the avatar is being worn locally, false otherwiseBoolNone
VisemeOculus viseme index (0-14). When using Jawbone/Jawflap, range is 0-100 indicating volumeIntSpeech
VoiceMicrophone volume (0.0-1.0)FloatSpeech
GestureLeftGesture from L hand control (0-7)IntIK
GestureRightGesture from R hand control (0-7)IntIK
GestureLeftWeightAnalog trigger L (0.0-1.0)†FloatPlayable
GestureRightWeightAnalog trigger R (0.0-1.0)†FloatPlayable
AngularYAngular velocity on the Y axisFloatIK
VelocityXLateral move speed in m/sFloatIK
VelocityYVertical move speed in m/sFloatIK
VelocityZForward move speed in m/sFloatIK
VelocityMagnitudeTotal magnitude of velocityFloatIK
UprightHow "upright" you are. 0 is prone, 1 is standing straight upFloatIK
GroundedTrue if player touching groundBoolIK
SeatedTrue if player in stationBoolIK
AFKIs player unavailable (HMD proximity sensor / End key)BoolIK
Expression1 - Expression16User defined param, Int (0-255) or Float (-1.0-1.0)Int / FloatIK or Playable
TrackingTypeSee description belowIntPlayable
VRModeReturns 1 if the user is in VR, 0 if they are notIntIK
MuteSelfReturns true if the user has muted themselves, false if unmutedBoolPlayable
InStationReturns true if the user is in a station, false if notBoolIK
EarmuffsReturns true if the user's Earmuff feature is on, false if notBoolPlayable
IsOnFriendsListReturns true if the user viewing the avatar is friends with the user wearing it. false locally.BoolOther
AvatarVersionReturns 3 if the avatar was built using VRChat's SDK3 (2020.3.2) or later, 0 if not.IntIK

"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.

Avatar Scaling Parameters

NameDescriptionTypeSync
ScaleModifiedReturns true if the user is scaled using avatar scaling, false if the avatar is at its default size.BoolPlayable
ScaleFactorRelation between the avatar's default height and the current height. An avatar with a default eye-height of 1m scaled to 2m will report 2.FloatPlayable
ScaleFactorInverseInverse relation (1/x) between the avatar's default height and the current height. An avatar with a default eye-height of 1m scaled to 2m will report 0.5. Might be inaccurate at extremes.FloatPlayable
EyeHeightAsMetersThe avatar's eye height in meters.FloatPlayable
EyeHeightAsPercentRelation of the avatar's eye height in meters relative to the default scaling limits (0.2-5.0). An avatar scaled to 2m will report (2.0 - 0.2) / (5.0 - 0.2) = 0.375.FloatPlayable

All of these parameters are read-only.

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 256 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.

Parameter TypeRangeMemory UsageNotes
int0-2558 bitsUnsigned 8-bit int.
float-1.0 to 1.08 bitsSigned 8-bit fixed-point decimal†.
boolTrue or False1 bit

† Remotely synced float values have 255 possible values, giving a precision of 1/127 over the network, and can store -1.0, 0.0, and 1.0 precisely. When updated locally, such as with OSC, float values are stored as native (32-bit) floating-point values in animators.

GestureLeft and GestureRight Values

GestureLeft and GestureRight use these as their values:

IndexGesture
0Neutral
1Fist
2HandOpen
3FingerPoint
4Victory
5RockNRoll
6HandGun
7ThumbsUp

Viseme Values

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

Viseme ParameterViseme
0sil
1pp
2ff
3th
4dd
5kk
6ch
7ss
8nn
9rr
10aa
11e
12i
13o
14u

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 mode meant to synchronize longer-running animation states. Updates every 0.1 to 1 seconds as needed based on parameter changes (1 to 10 updates per second), but you shouldn't rely on it for fast sync.
  • IK - A faster sync mode meant to synchronize frequently-changing values. Updates continuously every 0.1 seconds (10 updates per second), and interpolates float values locally for remote users. Depending on the parameter, this may also just be calculated based on the avatar's locally rendered IK state.

When an Expression Parameter is in-use in a Puppet menu, it automatically swaps from Playable to IK sync so you get the continuous update rate and smooth interpolation. When the menu is closed, it returns to Playable 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.

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.

ParameterDescription
0Uninitialized. Usually only occurs when the user is switching avatars and their IK isn't sending yet.
1Generic rig. The user might have tracking of any kind on, but the avatar is rigged as Generic,so tracking is ignored. Might be a desktop user if VRMode is 0.
2Only occurs with AV2,and therefore isn't a state you should expect to be in for very long for AV3 controllers on avatars. May still occur with SDK3 stations.
Hands-only tracking with no fingers. This will only occur in states that are transitions-- as in, you should expect TrackingType to change again, and the avatar should not stay in this state.
3Head and hands tracking. If VRMode is 1, this user is in 3-point VR. If VRMode is 0, this is a Desktop user in a humanoid avatar.
44-point VR user. Head, hands, and hip.
55-point VR user. Head, hands and feet tracked. Basically full Body Tracking but without the hip.
6Full Body Tracking VR user. Head, hands, hip, and feet tracked.

Expression Parameter Aliasing

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

When naming your own parameters, using forward slashes (/) will cause parameters to automatically organize in various selection dropdowns. For example, naming a parameter Toggles/Hat will make the menu selection show up as Toggles -> Hat when selecting parameters for things like Animator transitions and Expression Menus, while keeping the underlying parameter the same name. This doesn't change how parameters behave, it just makes it easier to work with large parameter lists.

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_surprised , 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.

Cross-Platform Parameter Sync

When using an avatar that has both Quest and PC versions uploaded, parameters are synced by their position in the parameters list and their parameter type, not by the names of the parameters. For a given parameter to sync between PC and Quest, it has to be in the same position in the parameter list, and have the same parameter type.

Given this, it can be a good idea to use the same Expression Parameters asset for both the PC and Quest versions of an avatar, even if one version doesn't make use of all the parameters.

Mismatched Parameter Type Conversion

When you choose a parameter type in your animator, it's a good idea to choose the same type as the built-in parameter or custom parameter you're trying to use. For example: If you use VRChat's built-in AFK parameter in your animator, you should choose the type bool.

However, you can choose a mismatched type for your parameters. VRChat will try convert the parameter's value to the type used by the animator. For example, if you choose the type float for your AFK parameter, VRChat will automatically set AFK to 1.0 or 0.0 instead of true or false. This also allows you to use the AFK parameter in your Animator's Blend Tree.

The table below shows how converting a mismatched parameter changes it.

Source TypeAnimator TypeConversion BehaviorExample
intfloatDirectly converted to float.11.0
intbool0 is false, anything else is true1true
floatintRounded to closest int (same as Mathf.Round)0.50, 0.61, 1.52
floatbool0.0 is false, anything else is true0.5true
boolinttrue is 1, false is 0true1
boolfloattrue is 1.0, false is 0.0true1.0