Photon Integration: Networked Movement

Networked Movement is the system that allows players to see each other move smoothly in real time.
In VR fangames, movement is fast, physics‑driven, and highly expressive — which makes syncing it across the network one of the hardest challenges.

This page explains how Photon handles movement, what should and shouldn’t be synced, and how to design a smooth, low‑latency movement system for VR multiplayer.

1. What Networked Movement Is

Networked Movement ensures that every player sees:

• Accurate player positions

• Smooth transitions between updates

• Correct body orientation

• Real‑time movement without jitter

• Predictable motion even with lag

Movement syncing is the backbone of VR multiplayer immersion.

2. Why VR Movement Is Hard to Sync

VR movement is:

• Fast

• Physics‑based

• Player‑controlled

• Highly reactive

• Dependent on hand motion

This means:

• You cannot sync physics directly

• You cannot sync rigidbodies

• You cannot sync every frame

• You cannot rely on root motion

Instead, you sync the player’s head and hands, and reconstruct movement locally.

3. The Correct Way to Sync VR Movement

You do NOT sync the player’s body.

You sync:

• Head

• Left hand

• Right hand

Then you rebuild the player’s movement locally using:

• Head position

• Hand velocity

• Hand direction

• Local physics

This is how Gorilla Tag‑style locomotion works.

4. What Should Be Synced

Only sync:

• Head position + rotation

• Left hand position + rotation

• Right hand position + rotation

Everything else is reconstructed locally.

This keeps bandwidth low and movement smooth.

5. What Should NOT Be Synced

To avoid lag, jitter, and bandwidth overload, do NOT sync:

• Rigidbody velocity

• Rigidbody forces

• Physics collisions

• Full body transforms

• Player root transform

• Entire player model

• Finger bones

• Animations

Photon is not designed to sync physics — it’s designed to sync transforms.

6. How Movement Appears Smooth to Other Players

Photon uses:

A. Interpolation

Smooths movement between network updates.

B. Extrapolation

Predicts where the player will be next.

C. Lag Compensation

Offsets network delay.

D. High Send Rates

VR requires 30–60 updates per second.

These systems work together to create smooth movement.

7. Recommended Send Rates

For VR movement:

• Send Rate: 30–60

• Serialization Rate: 30–60

Lower rates cause:

• Teleporting

• Jitter

• Delayed movement

• Desync during fast swings

Higher rates feel much more natural.

8. Player Root Position (Important)

The player’s root transform should NOT be synced.

Instead:

• The root follows the head

• The head is synced

• The hands are synced

• The body is reconstructed locally

This is how VR multiplayer avoids jitter and lag.

9. Movement Prediction

To reduce lag, you can use:

• Interpolation (smooths past → present)

• Extrapolation (predicts present → future)

• Velocity smoothing

• Rotation smoothing

Prediction is optional but improves quality.

10. Best Practices

• Sync only head + hands

• Never sync physics

• Use interpolation for smoothness

• Use high send rates for VR

• Keep player prefab lightweight

• Reconstruct movement locally

• Test with 6–10 players for performance

• Avoid RPC spam for movement