The document details the requirements and processes involved in clustered lighting and shading within a graphics framework, particularly focusing on data structures and pseudocode for optimizing light calculations and rendering. It discusses various techniques for managing light behavior, particle lighting, and post-processing optimizations. The conclusion hints at future developments and includes references and hiring information.

1. THE DEVIL IS IN THE DETAILS

2. Initial Requirements











3. Anatomy of a Frame
Frame Cost











4. Data Structure for Lighting & Shading










5. Preparing Clustered Structure




 𝑍𝑆𝑙𝑖𝑐𝑒 = 𝑁𝑒𝑎𝑟𝑧 × (
𝐹𝑎𝑟𝑧
𝑁𝑒𝑎𝑟𝑧
)
𝑠𝑙𝑖𝑐𝑒
𝑛𝑢𝑚 𝑠𝑙𝑖𝑐𝑒𝑠





6. Preparing Clustered Structure






//Pseudo-code - 1 job per depth slice ( if any item )
for ( y = MinY; y < MaxY; ++y ) {
for ( x = MinX; x < MaxX; ++x ) {
intersects = N planes vs cell AABB
if ( intersects ) {
Register item
}
}
}

7. Preparing Clustered Structure














8. Preparing Clustered Structure

9. Preparing Clustered Structure

10. Detailing the World










11. Detailing the World













12. Detailing the World

 𝑒0 𝑒1


const float4 albedo = tex2Dgrad( decalsAtlas, uv.xy * scaleBias.xy + scaleBias.zw, uvDDX, uvDDY );
𝑒
𝑒 𝑒
𝑒0 𝑥
𝑒1 𝑥 2 𝑥 𝑥
𝑒0 𝑦
𝑒1 𝑦 2 𝑦 𝑦
𝑒0 𝑧
𝑒1 𝑧 2 𝑧 𝑧
0 0 0 1
0.5
𝑠𝑖𝑧𝑒𝑋
0 0 0.5
0
0.5
𝑠𝑖𝑧𝑒𝑌
0 0.5
0 0
0.5
𝑠𝑖𝑧𝑒𝑍
0.5
0 0 0 1
∙

13. Detailing the World











14. Detailing the World

15. Detailing the World

16. Detailing the World

17. Detailing the World

18. Detailing the World

19. Detailing the World

20. Lighting











21. Lighting
//Pseudocode
ComputeLighting( inputs, outputs ) {
Read & Pack base textures
for each decal in cell {
early out fragment check
Read textures
Blend results
}
for each light in cell {
early out fragment check
Compute BRDF / Apply Shadows
Accumulate lighting
}
}

22. Lighting













23. Lighting











24. Lighting



25. Lighting

 




 




26. Transparents







27. Particle Lighting











28. Decoupled Particle Lighting











29. Decoupled Particle Lighting
//Pseudocode – Particle shading becomes something like this
Particles( inputs, outputs ) {
…
const float3 lighting = tex2D( particleAtlas, inputs.texcoord );
result = lighting * inputs.albedo;
…
}

30. Decoupled Particle Lighting









Particle Light Atlas

31. Decoupled Particle Lighting


32. Post-Process

33. Optimizing Data Fetching ( GCN )









34. Clustered Lighting Access Patterns

35. Clustered Lighting Access Patterns

36. Clustered Lighting Access Patterns

37. Clustered Lighting Access Patterns

38. Analyzing the Data








39. Leveraging Access Patterns










Thread X A B D
Thread Y B C E
Thread Z A C D E
Scalar A B C D E

40. Special Paths












41. Dynamic Resolution Scaling










42. Async Post Processing










43. GCN Wave Limits Tuning








44. GCN Register Usage










51. What’s next ?








52. Special Thanks







53. 

We are Hiring !

54. Thank you






55. References















56. Bonus Slides

57. Lighting
















58. Deferred Passes







