Eye tracking allows your avatar's eyes to follow your real-world eye movements in VR, and set up blinking animations. This feature is essential for natural-looking avatars in VRChat.

Mode Selection

The Eye Tracking panel offers two modes:

SDK3 Mode

Simplified setup for VRChat SDK3
Automatic bone rotation configuration
Direct eye bone assignment
Recommended for most users
Faster setup process

Legacy Mode

Complete eye tracking setup
Customizable eye movement
Advanced blinking controls
Shape key integration
More control over parameters

💡 Tip: Do not use Legacy Mode for VRChat, Legacy mode is only for other games like ChilloutVR, VRChat eye tracking is now set up in Unity.

SDK3 Mode Setup

SDK3 Mode provides a streamlined setup process.

Requirements

Eye bones in your armature
Head bone in your armature
Properly weighted eyes

Step-by-Step Setup

Select Mode:
- Choose SDK3 Mode in the panel
Select Bones:
- Head Bone: Select your head bone
- Left Eye Bone: Select left eye bone
- Right Eye Bone: Select right eye bone
Configure Movement:
- Cats will automatically set up rotation limits
- Eye bones will be configured for tracking
Test:
- Use the testing controls
- Verify eye movement is natural

That's it, not you have to set the rest up in Unity.

Legacy Mode Setup

Legacy Mode provides more control and options for other games or software like ChilloutVR.

Bone Selection

Head Bone

Select the main head bone
Used as reference for eye rotation
Usually named "Head" or "head"

Eye Bones

Left Eye Bone: Left eye control bone
Right Eye Bone: Right eye control bone
These bones should be parented to the head
Typically named "Eye_L" / "Eye_R" or similar

📝 Note: Cats can auto-detect bones with common names.

Shape Key Configuration

For blinking and eye animations:

Wink Shape Keys

Wink Left: Shape key for left eye closed
Wink Right: Shape key for right eye closed
Used for blinking and winking expressions

Lower Lid Controls

Lower Lid Left: Shape key for left lower lid
Lower Lid Right: Shape key for right lower lid
Creates more natural blink animations
Optional but recommended

Eye Movement Settings

Distance Adjustment:

Controls how far eyes can move
Higher values = more movement
Lower values = more subtle
Default is usually good

Rotation Controls:

X Axis: Horizontal movement (left/right)
Y Axis: Vertical movement (up/down)
Adjust these during testing

Additional Options

Disable Eye Blinking:

Prevents automatic blinking
Use if you want manual control
Or if model doesn't support blinking

Disable Eye Movement:

Locks eye rotation
Eyes won't follow gaze
Use for stylized or static eyes

Eye Distance:

Adjusts spacing between eye targets
Fine-tune for your model
Affects how eyes converge

Mesh Selection:

For multi-mesh models
Select which mesh contains shape keys
Usually the body or face mesh

Testing Mode

Both modes include testing features.

Eye Movement Testing

Real-Time Preview:

Test eye rotation in Blender
See how eyes move
Verify natural movement

X/Y Axis Controls:

Sliders to test horizontal/vertical movement
Move eyes left/right and up/down
Check full range of motion

Distance Adjustment:

Test how far eyes move
Adjust for your model's proportions

Reset Position:

Return eyes to center
Clear all test rotations
Start fresh

Blinking Controls

Blink Shape Testing:

Test wink shape keys
Verify eyelids close properly
Check both eyes individually

Lower Lid Animation:

Test lower lid movement
Ensure natural blink appearance
Verify shape key assignment

Animation Preview:

See full blink cycle
Check timing and smoothness

Workflow

Basic Eye Tracking Setup

Choose your mode (SDK3 for VRChat, Legacy for other games that need it)
Select bones:
- Head bone
- Left and right eye bones
If using Legacy, set up shape keys:
- Wink left/right
- Lower lids (optional)
Test eye movement:
- Use X/Y controls
- Verify natural motion
Test blinking:
- Check blink shapes
- Adjust if needed
Export your model

Advanced Setup (Legacy Mode)

Select Legacy Mode
Configure bones as above
Set up all shape keys:
- Wink left
- Wink right
- Lower lid left
- Lower lid right
Adjust settings:
- Eye distance
- Movement range
- Rotation limits
Test thoroughly:
- All directions
- Blinking
- Combinations
Fine-tune:
- Adjust distances
- Tweak shape key strength
Export

Tips and Best Practices

Bone Setup

Eye Bone Position:

Should be centered in the eyeball
Not at the surface
Rotation pivot point

Eye Bone Rotation:

Should be aligned with head
Z-axis pointing forward (usually)
Test in multiple directions

Weight Painting

Eye Mesh Weights:

Eyes should be 100% weighted to their eye bones
No weight bleeding to other bones
Clean weight distribution

Eyelid Weights:

Can have mixed weights between head and eye bones
Depends on desired deformation
Test blinking to verify

Shape Key Creation

Good Wink Shape Keys:

Eyes fully closed
Natural eyelid position
Matches eye shape
No clipping or gaps

Good Lower Lid Shape Keys:

Subtle movement
Follows upper lid motion
Natural squint appearance
Optional but adds realism

Testing

In Blender:

Test all directions
Check at extreme ranges
Verify blinking
Look from multiple angles

In VRChat:

Test with actual eye tracking
Check with others
Verify in mirrors
Adjust if needed

Common Issues

Eyes Don't Move

Possible causes:

Eye bones not selected
Eye bones not weighted properly
Movement disabled in settings

Solutions:

Verify bone selection
Check weight painting on eye meshes
Ensure "Disable Eye Movement" is off

Eyes Look Weird When Moving

Possible causes:

Incorrect bone rotation
Wrong pivot points
Bad weight painting

Solutions:

Check eye bone rotation (should match head forward direction)
Verify bone is centered in eye mesh
Fix weight painting on eyes

Blinking Doesn't Work

Possible causes:

Shape keys not assigned
Wrong mesh selected
Blinking disabled

Solutions:

Verify wink shape keys are assigned
Select correct mesh in panel
Check "Disable Eye Blinking" is off

Eyes Cross or Diverge Incorrectly

Possible causes:

Eye distance setting wrong
Bone positions incorrect

Solutions:

Adjust eye distance slider
Verify eye bones are positioned correctly
Test with different distance values

Eyelids Clip Through Eyes

Possible causes:

Shape keys too extreme
Mesh topology issues

Solutions:

Adjust shape keys to be less extreme
Fix mesh topology around eyes
Use shape key drivers to limit range

Integration Notes

With Material Combiner

⚠️ Important: Set up eye tracking AFTER using Material Combiner. Material Combiner can cause shape keys to become misaligned if run after eye tracking setup.

Recommended order:

Import model
Combine materials / Create atlas
Set up eye tracking
Set up visemes
Export