Photon Integration: Syncing Hands

Syncing hands is one of the core requirements for VR multiplayer.
Hands are the most expressive part of a VR player’s avatar — they show direction, gestures, interactions, and movement.
If hand syncing is smooth, the entire multiplayer experience feels alive.
If it’s jittery or delayed, the game feels broken.

This page explains how to sync VR hands using Photon, how to structure your hand objects, and how to achieve smooth, low‑latency replication.

1. What Hand Syncing Does

Hand syncing ensures that every player sees:

• The correct hand positions

• The correct hand rotations

• Gestures or finger tracking (optional)

• Smooth interpolation between updates

Hands must update quickly and consistently to feel natural in VR.

2. How Photon Syncs Hands

Photon uses serialization to send transform data across the network.

Each hand typically has:

• A PhotonView

• A sync script (PhotonTransformView or custom)

• A local VR controller reference (for the owner)

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

3. Recommended Hand Sync Architecture

Your player prefab should include:

Player

│

├── Head (synced)

├── LeftHand (synced)

└── RightHand (synced)

Each hand object should have:

• PhotonView

• Sync script

• Hand model / mesh

• Optional finger tracking

Hands should NOT be children of a synced root object — they should sync individually for accuracy.

4. Syncing Position & Rotation

A. Using PhotonTransformView (simple)

Good for beginners, but less smooth.

B. Using a custom sync script (recommended)

Allows:

• Interpolation

• Extrapolation

• Smoothing

• Lag compensation

A custom script gives you full control over how hands move on remote players.

5. Interpolation (Why It Matters)

Interpolation smooths out movement between network updates.

Without interpolation:

• Hands jitter

• Movement looks robotic

• Fast swings look choppy

With interpolation:

• Hands glide smoothly

• Gestures look natural

• Movement feels responsive

VR absolutely requires interpolation.

6. Send Rate Recommendations

VR hands move fast — they need higher update rates.

Recommended:

• Send Rate: 30–60

• Serialization Rate: 30–60

Lower rates cause:

• Lag

• Teleporting hands

• Desync during fast movement

Higher rates use more bandwidth but feel much better.

7. Finger Tracking (Optional)

If your game uses finger tracking (Index controllers, Quest hand tracking):

You can sync:

• Trigger value

• Grip value

• Thumb position

• Finger curls

These should be synced using:

• Custom Player Properties (for slow‑changing values)

• RPCs (for gestures)

• Serialization (for continuous finger data)

Most fangames skip finger tracking to save bandwidth

8. What NOT to Sync

To avoid lag and bandwidth issues, do NOT sync:

• Physics on hands

• Colliders

• Rigidbody forces

• Full finger bones (too heavy)

• Large data packets

• Constant RPC spam

Only sync the essentials: position + rotation.

9. Best Practices

• Sync each hand separately

• Use interpolation for smooth movement

• Keep hand models lightweight

• Avoid syncing physics

• Use high send rates for VR

• Use custom scripts for better smoothing

• Test with 6–10 players to ensure stability