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Avatar standards

Skeleton

Warning

The root bone is necessary to keep the avatar's feet on the floor for animations such as jumping.

It should start at 0, 0, 0 and end where the hip bone starts. The hip bone must be parented to it.

It's not shown in the pictures because it easily obscures the other bones, but definitely add it! The blender addon will do this for you when exporting.

Legs Body Hand

Root
`―― Hips
    |―― LeftUpLeg
    |   `―― LeftLeg
    |       `―― LeftFoot
    |           `―― LeftToeBase
    |―― RightUpLeg
    |   `―― RightLeg
    |       `―― RightFoot
    |           `―― RightToeBase
    `―― Spine
        `―― Spine1
            `―― Spine2
                |―― Neck
                |   `―― Head
                |       |―― HeadTop_End
                |       |―― LeftEye
                |       `―― RightEye
                |―― LeftShoulder
                |   `―― LeftArm
                |       `―― LeftForeArm
                |           `―― LeftHand
                |               |―― LeftHandThumb1
                |               |   `―― LeftHandThumb2
                |               |       `―― LeftHandThumb3
                |               |―― LeftHandIndex1
                |               |   `―― LeftHandIndex2
                |               |       `―― LeftHandIndex3
                |               |―― LeftHandMiddle1
                |               |   `―― LeftHandMiddle2
                |               |       `―― LeftHandMiddle3
                |               |―― LeftHandRing1
                |               |   `―― LeftHandRing2
                |               |       `―― LeftHandRing3
                |               `―― LeftHandPinky1
                |                   `―― LeftHandPinky2
                |                       `―― LeftHandPinky3
                `―― RightShoulder
                    `―― RightArm
                        `―― RightForeArm
                            `―― RightHand
                                |―― RightHandThumb1
                                |   `―― RightHandThumb2
                                |       `―― RightHandThumb3
                                |―― RightHandIndex1
                                |   `―― RightHandIndex2
                                |       `―― RightHandIndex3
                                |―― RightHandMiddle1
                                |   `―― RightHandMiddle2
                                |       `―― RightHandMiddle3
                                |―― RightHandRing1
                                |   `―― RightHandRing2
                                |       `―― RightHandRing3
                                `―― RightHandPinky1
                                    `―― RightHandPinky2
                                        `―― RightHandPinky3

Blendshapes

You don't have to add every blendshape, just the ones you want to use.

Basic blendshapes

These blendshapes are the most used.

  • EyeBlink_L Blinking action for the left eye
  • EyeBlink_R Blinking action for the right eye
  • JawOpen Opening of the jaw

Audio blendshapes

These blendshapes are used when you speak.

Your eyebrows are blendshapes that react to a change in volume. They will move upwards when your voice gets louder. These include:

  • BrowsU_C Center of the brow going up
  • BrowsU_L Outside corner of the left brow going up
  • BrowsU_L Outside corner of the right brow going up

Other audio blendshapes are randomly mixed when you speak. These include:

  • MouthSmile_L Left side of the mouth lifting up to a smile
  • MouthSmile_R Right side of the mouth lifting up to a smile
  • LipsFunnel Funneling of the lips, as when you say “Oh!”
  • LipsUpperClose Upper lips rolled inwards

Eyelid offset

To ensure that the top of the eyelid rests on the iris, blendshapes are used to track the current position of the eye along with your head orientation.

  • EyeBlink_L Blinking action for the left eye
  • EyeBlink_R Blinking action for the right eye
  • EyeOpen_L Opening of left eye
  • EyeOpen_R Opening of right eye
  • BrowsD_L Outside corner of the left brow moving down
  • BrowsD_R Outside corner of the right brow moving down

We apply a small procedural offset to the blendshape coefficients to prevent sleepy or crazy eye lids:

  • If you are looking straight ahead: The EyeBlink and EyeOpen coefficients will be 0.

  • If your eyes begin to look upward: EyeBlink, EyeOpen, and BrowsU start changing in value, reaching the values of -1, 1, and 0.5 respectively at 16.3 degrees. This will have the effect of raising your lids and brows as you look upward.

  • If your eyes begin to look downward: EyeBlink and EyeOpen start changing in value. EyeBlink reaches a value of 0.5 at 32 degrees. EyeOpen will reach a value of 0.5 at 27 degrees. This will have the effect of lowering your lids as you look downward.

Tweaks to your blendshapes can be made with a 3D modeling tool, or directly in your avatar’s FST file. In the FST file, blendshapes are defined with the syntax:

bs = [blendshape constant] = [your blendshape name] = [value between 0 and 1]

Here is an example of modifying your blendshapes in your FST file:

bs = BrowsU_L = head_BS_brow_up = 0.3
bs = BrowsU_C = head_BS_brow_up = 0.3
bs = BrowsU_R = head_BS_brow_up = 0.3
bs = BrowsD_R = head_BS_brow_down = 0.5
bs = BrowsD_L = head_BS_brow_down = 0.5
bs = EyeBlink_L = head_BS_L_eye_close = 1
bs = EyeBlink_R = head_BS_R_eye_close = 1
bs = EyeOpen_L = head_BS_L_eye_open = 1
bs = EyeOpen_R = head_BS_R_eye_open = 1
bs = JawOpen = JawOpen = 1
bs = MouthSmile_R = head_BS_L_smile = 0.6
bs = MouthSmile_L = head_BS_R_smile = 0.6
bs = LipsFunnel = head_BS_oo = 0.5
bs = LipsUpperClose = head_BS_mouth_down = 0.1
Last update: October 8, 2021