Performance Optimization: Getting 60+ FPS with Beautiful Water

Beautiful water shouldn't mean sacrificing performance. This guide shows you how to achieve both.

🎯 Performance Goals

Before optimizing, define your targets:

Platform	Target FPS	GPU Budget
PC High-End	60-144	8-12ms
PC Mid-Range	60	12-16ms
Console	30-60	16-33ms
VR	90	11ms

Golden Rule

Profile first, optimize second. Never guess — measure actual bottlenecks.

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📊 Profiling Your Water

Essential Console Commands

stat gpu              // GPU timing breakdown
stat unit             // Frame timing overview
stat scenerendering   // Render thread details
profilegpu            // Detailed GPU profiler
stat memory           // Memory usage

What to Look For

Stat	Target	If Too High
GPU Time	Under 12ms	Reduce visual quality
Game Thread	Under 8ms	Optimize BP logic
Draw Calls	Under 2000	Enable instancing
Triangles	Under 5M	Adjust QuadTree

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🌊 Wave System Optimization

FFT Resolution (NextGen)

The FFT grid resolution has the biggest performance impact:

Resolution	Quality	Performance Cost
512x512	Best	High
256x256	Great	Medium
128x128	Good	Low

How to adjust:

1. Select your Ocean actor
2. Find FFT Settings category
3. Lower Resolution value

Wave Layers (Legacy)

Legacy uses layered Gerstner waves:

Layers	Quality	Cost
4	Full detail	1.0x
3	Very good	0.75x
2	Acceptable	0.5x
1	Minimal	0.25x

Recommendation: Start with 2 layers, add more only if needed.

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🔲 QuadTree LOD Settings

The QuadTree mesh system is key to performance:

Distance-Based LOD

Adjust how quickly detail reduces with distance:

Near LOD Distance: 1000     // Full detail within 10m
Mid LOD Distance: 5000      // Medium detail 10-50m
Far LOD Distance: 20000     // Low detail 50-200m

Tessellation Settings

Setting	Performance Impact	Visual Impact
Max Tessellation	High	Wave detail
LOD Multiplier	Medium	Distance quality
Screen Size Threshold	Medium	Mesh density

Quick optimization:

• Halve Max Tessellation → 2x performance gain
• Double LOD Distances → Significant FPS boost

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🏖️ Shore Effects Optimization

Shore effects can be expensive. Here's how to optimize:

Foam

Setting	Value	Impact
Foam Samples	8→4	-30% GPU
Foam Resolution	512→256	-40% memory
Update Frequency	Every frame→Every 2 frames	-50% cost

Shore Waves

• Disable if your scene doesn't have beaches
• Reduce wave segments from 32 to 16
• Limit shore wave distance to nearby camera areas

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🏊 Buoyancy Optimization

Pontoon Count

More pontoons = more accurate floating = more CPU cost

Object Type	Recommended Pontoons
Small debris	1
Barrels/crates	3-4
Boats	5-8
Ships	8-12

Query Optimization

// In your buoyancy component
Buoyancy Update Frequency: 0.02  // Every 20ms instead of every frame
Use Async Queries: true          // Non-blocking water height queries

Culling

Disable buoyancy for off-screen objects:

// In your game mode or manager
OnActorOutOfRange → Disable Buoyancy Component
OnActorInRange → Re-enable Buoyancy Component

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🌅 Visual Quality Settings

Reflection Settings

Mode	Quality	Cost
Lumen	Best	High
Screen Space	Good	Medium
Planar	Great	Medium-High
Cubemap Only	Acceptable	Low

Recommendation: Use Screen Space for most games.

Refraction

Setting	Impact
Refraction Quality	Medium → Low saves 1-2ms
Depth Sampling	Half-res saves 20%

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📱 Platform-Specific Tips

PC Scalability

Create multiple quality presets:

// UltraQuality
FFT_Resolution: 512
WaveLayers: 4
MaxTessellation: 64
ReflectionMode: Lumen

// HighQuality  
FFT_Resolution: 256
WaveLayers: 3
MaxTessellation: 32
ReflectionMode: ScreenSpace

// MediumQuality
FFT_Resolution: 128
WaveLayers: 2
MaxTessellation: 16
ReflectionMode: Cubemap

// LowQuality
Use Oceanology Legacy instead

Console Optimization

For PS5/Xbox Series X:

• Use NextGen with Medium settings
• Enable Variable Rate Shading (VRS)
• Use Async Compute for FFT

For PS4/Xbox One:

• Use Oceanology Legacy
• Limit to 2 wave layers
• Reduce QuadTree density

VR Optimization

VR is demanding — every millisecond counts:

1. Use Oceanology Legacy (not NextGen)
2. Disable post-processing underwater effects
3. Reduce all distances by 50%
4. Use fixed foveated rendering if available
5. Target 90 FPS minimum

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⚡ Quick Optimization Checklist

Immediate Wins (Big Impact, Easy)

• Lower FFT resolution (512→256)
• Reduce wave layers (4→2)
• Increase LOD distances
• Disable unused shore effects

Medium Effort

• Optimize QuadTree settings
• Reduce pontoon counts
• Enable async buoyancy queries
• Cull off-screen water interaction

Advanced

• Profile GPU to find exact bottlenecks
• Create scalability presets
• Implement distance-based quality switching
• Custom LOD for different water bodies

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📈 Expected Performance Gains

Following this guide, expect:

Change	FPS Gain
FFT 512→256	+20-30%
Wave layers 4→2	+15-25%
QuadTree optimization	+10-20%
Buoyancy async	+5-10%
Combined	+50-80%

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🔧 Debugging Performance

If still having issues:

1. Isolate the water

   • Create empty level with only ocean
   • Measure baseline FPS
   • Add elements one by one

2. Check for conflicts

   • Other water plugins?
   • Heavy post-processing?
   • Particle systems?

3. GPU vs CPU bound

   • stat unit shows which is limiting
   • GPU: reduce visual quality
   • CPU: reduce complexity/queries

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📚 More Resources

• QuadTree Documentation
• Presets Guide
• Community Discord — #optimization channel

Performance optimization is iterative. Start with the biggest wins and work down. Your players will thank you for smooth, beautiful water!