Photon Integration: Syncing Head

Syncing the player’s head is the foundation of VR multiplayer.
The head determines where the player is looking, how their body is oriented, and how other players interpret their movement.
If the head is synced smoothly, the entire avatar feels natural and believable.

This page explains how to sync the VR headset’s position and rotation using Photon, how to structure your head object, and how to achieve smooth, low‑latency replication.

1. What Head Syncing Does

Head syncing ensures that every player sees:

• The correct head position

• The correct head rotation

• The correct viewing direction

• Smooth interpolation between updates

This is essential for immersion and player interaction.

2. How Photon Syncs the Head

Photon uses serialization to send transform data across the network.

The head object typically includes:

• A PhotonView

• A sync script (PhotonTransformView or custom)

• A VR headset reference (for the owner)

The owner writes the head’s position/rotation.
Other players read and interpolate it.

3. Recommended Head Sync Architecture

Your player prefab should include:

Player

│

├── Head (synced)

├── LeftHand (synced)

└── RightHand (synced)

The Head object should contain:

• PhotonView

• Sync script

• Head model (optional)

• Cosmetic attach points (hats, masks, etc.)

The head should be synced independently, not as a child of a synced root.

4. Syncing Position & Rotation

A. PhotonTransformView (simple)

Easy to set up, but less smooth.

B. Custom sync script (recommended)

Allows:

• Interpolation

• Extrapolation

• Lag compensation

• Smoothing curves

VR benefits heavily from custom smoothing logic.

5. Interpolation (Why It Matters)

Interpolation smooths out movement between network updates.

Without interpolation:

• Head jitter

• Snapping

• Delayed rotation

• Unnatural movement

With interpolation:

• Smooth head movement

• Natural looking direction

• Stable avatar orientation

This is critical for VR comfort.

6. Send Rate Recommendations

The head moves slower than hands, but still needs high update rates.

Recommended:

• Send Rate: 30–60

• Serialization Rate: 30–60

Lower rates cause:

• Head jitter

• Delayed rotation

• Desync during fast turns

Higher rates improve smoothness.

7. What NOT to Sync

To avoid lag and bandwidth issues, do NOT sync:

• Physics on the head

• Colliders

• Rigidbody forces

• Full body models

• Large data packets

• Constant RPC spam

Only sync the essentials: position + rotation.

8. Cosmetic Attach Points

The head often contains attach points for:

• Hats

• Masks

• Glasses

• Head accessories

These should NOT be synced via transforms.
Instead, sync cosmetic IDs using Custom Player Properties.

Photon will then load the correct cosmetic locally.

9. Best Practices

• Sync the head separately from the body

• Use interpolation for smooth movement

• Keep the head model lightweight

• Avoid syncing physics

• Use high send rates for VR

• Use custom scripts for better smoothing

• Test with multiple players to ensure stability