Unity Performance Optimization

Overview

Performance optimization for Unity games focusing on profiling and systematic optimization.

Foundation Required: unity-csharp-fundamentals (TryGetComponent, FindAnyObjectByType, null-safe coding)

Core Topics:

• Unity Profiler analysis
• Draw call reduction
• GPU instancing and SRP Batcher
• LOD (Level of Detail)
• Occlusion culling
• Object pooling
• Memory optimization

Quick Start

Collection & Object Pooling

GC-free pooling is critical for performance. Use Unity's built-in UnityEngine.Pool namespace (2021.1+):

using UnityEngine.Pool;

// Temporary collection pooling - eliminates GC spikes
List<Enemy> enemies;
using (ListPool<Enemy>.Get(out enemies))
{
    GetComponentsInChildren(enemies);
    ProcessEnemies(enemies);
} // Auto-released

See unity-collection-pool skill for comprehensive patterns:

• ListPool, HashSetPool, DictionaryPool for temporary collections
• ObjectPool for component/prefab pooling
• Advanced patterns: Keyed pools, auto-return, ECS integration

Performance Targets

• Mobile: 30-60 FPS, <100 draw calls
• Desktop: 60+ FPS, <500 draw calls
• VR: 90 FPS minimum, <200 draw calls

Profiling Workflow

1. Profile first: Identify actual bottleneck (CPU/GPU/Memory)
2. Measure baseline: Record before optimization
3. Optimize bottleneck: Focus on biggest impact
4. Measure improvement: Validate changes
5. Repeat: Until target performance reached

Optimization Checklist

CPU Optimization

• ✅ Reduce Update/FixedUpdate calls
• ✅ Object pooling for frequently spawned objects
• ✅ Cache component references in Awake/Start
• ✅ Use events instead of polling

GPU Optimization

• ✅ Static batching for static objects
• ✅ GPU instancing for identical meshes
• ✅ Reduce SetPass calls via material sharing
• ✅ LOD groups for distant objects
• ✅ Occlusion culling for large scenes

Memory Optimization

• ✅ Texture compression
• ✅ Mesh optimization (reduce vertex count)
• ✅ Audio compression and streaming
• ✅ Asset bundle management
• ✅ Unload unused assets
• ✅ Collection pooling (see unity-collection-pool skill)

Related Skills

• unity-collection-pool: GC-free collection management with ListPool, HashSetPool, DictionaryPool, and ObjectPool. Essential for eliminating GC spikes.

Best Practices

1. Profile on target platform: Editor performance differs
2. Optimize systematically: Measure, optimize, validate
3. Quality settings: Provide options for different hardware
4. Balance visuals vs performance: Adjust based on target
5. Test on low-end: Ensure minimum spec performance