Making of Delta Building Visualization enviorment w/ Compute - - PowerPoint PPT Presentation

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Making of Delta Building Visualization enviorment w/ Compute - - PowerPoint PPT Presentation

Jan 07, 2024 373 likes •996 views

Making of Delta Building Visualization enviorment w/ Compute Shaders Kristo Mnna Who am I Hobbyist solo game developer Unity3D Project POMPEII Delta building visualization project Who am I Hobbyist solo game developer Unity3D Who am I

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Making of Delta Building Visualization enviorment w/ Compute Shaders

Kristo Männa

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Who am I

Hobbyist solo game developer Unity3D Project POMPEII Delta building visualization project

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Who am I

Hobbyist solo game developer Unity3D

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Who am I

Hobbyist solo game developer Unity3D Project POMPEII

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Who am I

Hobbyist solo game developer Unity3D Project POMPEII Delta building visualization project

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Topics

What are compute shaders Introduction to compute shaders (using Unity) Breakdown of Delta Building Visualization effects

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Topics

What are compute shaders Introduction to compute shaders (using Unity) Breakdown of Delta Building Visualization effects

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SLIDE 8

Topics

What are compute shaders Introduction to compute shaders (using Unity) Breakdown of Delta Building Visualization effects

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Topics

What are compute shaders Introduction to compute shaders (using Unity) Breakdown of Delta Building Visualization effects

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What are compute shaders?

GPU is very good at parallel processing (like really good) This power is underutilized

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What are compute shaders?

GPU is very good at parallel processing (like really good) This power is underutilized Thats where Compute Shaders come in

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What are compute shaders?

GPU is very good at parallel processing (like really good) This power is underutilized Thats where Compute Shaders come in Use GPU for other things besides graphics

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What are compute shaders?

GPU is very good at parallel processing (like really good) This power is underutilized Thats where Compute Shaders come in Use GPU for other things besides graphics

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How to use a Compute Shader

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How to use a Compute Shader

Normal code vs. cs code

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How to use a Compute Shader

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How to use a Compute Shader

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How to use a Compute Shader

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How to use a Compute Shader

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How to use a Compute Shader

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When to use compute shaders

A lot of operations that can be done in parallel

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When to use compute shaders

A lot of operations that can be done in parallel

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When to use compute shaders

A lot of operations that can be done in parallel

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When to use compute shaders

A lot of operations that can be done in parallel

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When to use compute shaders

A lot of operations that can be done in parallel

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Quick demo Batch rendering in unity

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Quick demo - Batch rendering in unity

  • 100 x 100 = 100 000 objects
  • GPU: GTX 1070 TI
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Quick demo - Batch rendering in unity

  • 100k Capsule GameObjects
  • 30-40 fps
  • Can use Unity’s static batching
  • Best approach for lower end GPUs

Standard rendering

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Quick demo - Batch rendering in unity

  • 100k Capsule GameObjects
  • GPU Instancing enabled shaders
  • 50-60 fps
  • For lower end about the same performance as Standard
  • For Mid-Higher end meaningfully better

GPU Instanced rendering

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Quick demo - Batch rendering in unity

  • 100k Capsule meshes
  • Custom shaders
  • must call draw from code
  • 300-600 fps
  • For lower end can be worse that previous methods
  • For Mid-Higher end way better

Manual Instanced rendering

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Quick demo - Batch rendering in unity

  • 1 Million quads
  • Simpler, smaller mesh improves performance
  • Lighter shader improves performance

Manual Instanced rendering

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Delta Building Visualization project (DBV)

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DBV effects

  • Individually animated crowd rendering
  • Bonus: Bubbles
  • 1 million grass object rendering
  • Cloud shadows
  • Dynamic snow tracks
  • Falling snow
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DBV effects

  • Individually animated crowd rendering
  • Bonus: Bubbles
  • 1 million grass object rendering
  • Cloud shadows
  • Dynamic snow tracks
  • Falling snow
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DBV effects

  • Individually animated crowd rendering
  • Bonus: Bubbles
  • 1 million grass object rendering
  • Cloud shadows
  • Dynamic snow tracks
  • Falling snow
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DBV effects

  • Individually animated crowd rendering
  • Bonus: Bubbles
  • 1 million grass object rendering
  • Cloud shadows
  • Dynamic snow tracks
  • Falling snow
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DBV effects

  • Individually animated crowd rendering
  • Bonus: Bubbles
  • 1 million grass object rendering
  • Cloud shadows
  • Dynamic snow tracks
  • Falling snow
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DBV effects

  • Individually animated crowd rendering
  • Bonus: Bubbles
  • 1 million grass object rendering
  • Cloud shadows
  • Dynamic snow tracks
  • Falling snow
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2000 Animated Agent rendering

Requirements:

  • max 2000 actors → max visible actors ~1500
  • Every actor has animations
  • Need to render them all
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2000 Animated Agent rendering

Naive approach: 1. Have two gameObject pools

a. Far away actors b. Close animated actors

2. Based on distance to camera render actors with objects from first or second pool

  • Very slow for 50+ animators
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2000 Animated Agent rendering

Used approach: 1. Bake animations to a texture 2. Only have one pool for all actors 3. Render visible actors with that pool

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Bubbles

Requirements:

  • Actors sometimes create bubbles
  • Bubbles are animated
  • max 500 bubbles at once

Used approach:

  • GPU instanced billboard shader
  • Bubble pool
  • Simple procedural scale animations
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1 Million grass object rendering

Requirements:

  • There is some grass outside the building
  • Would be nice if it looked like real grass
  • Need to handle 1 million grass objects
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1 Million grass object rendering

Naive approach: 1. Place down GPU instanced grass GameObjects 2. Let unity handle culling and batching Works okay for sub 10 000 grass objects ...but we need 1 million

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1 Million grass object rendering

Used approach: 1. Bake grass object positions 2. Using compute shader apply:

a. Frustum culling b. Distance culling c. 3D dither distance culling

3. Render visible with Graphics.DrawMeshInstanced()

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1 Million grass object rendering

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1 Million grass object rendering

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1 Million grass object rendering

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Cloud shadows

Requirements:

  • Would be nice if could visualize cloudiness somehow

Naive approach:

  • Use Unity’s projector component to render cloud shadows onto ground
  • Will have to affected objects twice

Used approach:

  • Same as naive
  • Ok since only one object to re-render
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Cloud shadows

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Dynamic snow tracks

Requirements:

  • Would be nice if could visualize snow tracks for actors
  • Will need to create tracks for 2000 actors every frame
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Dynamic snow tracks

Used approach: 1. Send actor positions to compute shader 2. Draw to splatmap 3. Tessellate a plane 4. Use vertex displacement

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Dynamic snow tracks

Requirements:

  • Would be nice if could visualize snow tracks for actors
  • Will need to create tracks for 2000 actors every frame
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Dynamic snow tracks

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Dynamic snow tracks

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Snowflakes

Naive approach:

  • Use Unity’s particle system
  • Very slow for 1000+ particles since CPU based
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Snowflakes

Used approach

  • Using compute shader cull and apply velocity to particles
  • Use DrawMeshInstanced() to draw visible snowflakes
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Conclusion

Learned about: 1. Compute shaders 2. How and where to use them 3. Breakdown of some simple DBV effects

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Any final questions?

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Peace!