VR Performance Guide

Performance targets, optimization techniques, and Quest-specific considerations.

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Performance Targets

Frame Rate

Platform	Minimum	Target
Quest 2	72 FPS	90 FPS
Quest 3	72 FPS	120 FPS

Frame budget at 72 FPS: 13.9ms per frame

Resource Budgets

Resource	Target	Maximum
Draw calls	100	150
Triangles	300k	500k
Active enemies	6	8
Active VFX	15	20

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VR-Specific Rules

Never Do

Action	Problem
Move camera transform directly	Causes motion sickness
Change camera FOV	VR FOV is fixed by hardware
Disable head tracking	Breaks spatial awareness
Use Instantiate in gameplay	Causes frame spikes
Block main thread	Tracking freezes

Always Do

Action	Reason
Move XR Rig, not camera	Maintains tracking
Use Time.deltaTime	Frame-rate independent
Pool all spawned objects	Avoids GC spikes
Cache GetComponent results	Reduces per-frame cost
Unsubscribe events in OnDisable	Prevents memory leaks

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Optimization Techniques

Rendering

• Enable Single Pass Instanced stereo rendering
• Use GPU instancing for repeated meshes
• Enable foveated rendering on Quest
• Aggressive LOD groups
• Bake lighting where possible
• Limit real-time shadows

Physics

• Use layer matrix to limit collision checks
• Prefer trigger colliders over continuous collision
• Update NavMesh paths at intervals (0.2s)
• Use OverlapSphereNonAlloc

Scripts

• Minimize Update() logic
• Use priority update system for enemies
• Cache all component references
• Avoid LINQ in hot paths
• Use StringBuilder for string operations

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Update Manager

Centralized update system with priority-based throttling.

Source: GameUpdateManager.cs

public enum UpdatePriority { High, Medium, Low }

[DefaultExecutionOrder(-99)]
public class GameUpdateManager : MonoBehaviour
{
    public static GameUpdateManager Instance { get; private set; }

    private readonly List<IUpdateable> _highPriorityUpdates = new();
    private readonly List<IUpdateable> _mediumPriorityUpdates = new(); 
    private readonly List<IUpdateable> _lowPriorityUpdates = new();

    private const float MediumPriorityInterval = 0.2f;
    private const float LowPriorityInterval = 0.4f;

    private void Update()
    {
        UpdateHighPriority();    // Every frame
        UpdateMediumPriority();  // Every 0.2s
        UpdateLowPriority();     // Every 0.4s
    }

    public void Register(IUpdateable updateable, UpdatePriority priority)
    {
        switch (priority)
        {
            case UpdatePriority.High:
                _highPriorityUpdates.Add(updateable);
                break;
            case UpdatePriority.Medium:
                _mediumPriorityUpdates.Add(updateable);
                break;
            case UpdatePriority.Low:
                _lowPriorityUpdates.Add(updateable);
                break;
        }
    }

    public void Unregister(IUpdateable updateable)
    {
        if (_highPriorityUpdates.Remove(updateable)) return;
        if (_mediumPriorityUpdates.Remove(updateable)) return;
        _lowPriorityUpdates.Remove(updateable);
    }
}

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Object Pooling

All spawned objects use GamePoolManager to avoid runtime allocations.

Source: GamePoolManager.cs

public class GamePoolManager : MonoBehaviour
{
    public static GamePoolManager Instance { get; private set; }

    private readonly Dictionary<EnemyData, ObjectPool<GameObject>> _enemyPoolDictionary = new();
    private readonly Dictionary<ParticleData, ObjectPool<GameObject>> _particlePoolDictionary = new();

    public GameObject GetEnemyPrefab(EnemyData data, Vector3 position, Quaternion rotation)
    {
        if (!_enemyPoolDictionary.TryGetValue(data, out var pool))
            return null;

        var obj = pool.Get();
        obj.transform.SetPositionAndRotation(position, rotation);
        obj.GetComponent<EnemyController>()?.OnSpawn(data);
        obj.SetActive(true);
        return obj;
    }

    public void ReturnEnemyPrefab(EnemyController enemy)
    {
        if (!enemy) return;

        if (_enemyPoolDictionary.TryGetValue(enemy.Data, out var pool))
            pool.Release(enemy.gameObject);
        else
            Destroy(enemy.gameObject);
    }
}

Priority Routing

VFX and audio have priority systems to prevent overload.

if (!_vfxRouter.CanSpawn(data.Priority))
    return null;

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Quest Build Settings

Player Settings

Setting	Value
Graphics API	Vulkan
Color Space	Linear
Scripting Backend	IL2CPP
Architecture	ARM64
Managed Stripping	Medium

Quality Settings

Setting	Value
Pixel Light Count	1-2
Texture Quality	Half Res
Anti-Aliasing	4x MSAA
Shadows	Disabled or blob only

XR Settings

Setting	Value
Stereo Rendering	Single Pass Instanced
Low Overhead Mode	Enabled
Phase Sync	Enabled

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Profiling

Tools

Tool	Purpose
Unity Profiler	CPU/GPU timing
Frame Debugger	Draw call analysis
Memory Profiler	Allocation tracking
OVR Metrics Tool	Quest-specific metrics

Key Metrics

• GPU time per frame
• Draw call count
• SetPass calls
• GC allocations
• Memory usage

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Common Issues

Issue	Solution
Frame drops	Profile GPU, reduce draw calls
Tracking loss	Never disable XR camera
Motion sickness	Add comfort options
Memory growth	Pool objects, unload unused
Thermal throttling	Reduce quality settings