1 / 34

Raytracing Prefiltered Occlusion for Aggregate Geometry

This paper presents advancements in ray tracing performance by utilizing prefiltered occlusion techniques for aggregate geometry. Key areas of focus include enhancing hardware efficiency, optimizing single-ray intersection speed, and reducing sample counts through importance sampling and prefiltering methods for soft shadows. Employing a bounding volume hierarchy facilitates improved ray intersection and update time. The results demonstrate significant improvements in rendering times for complex scenes, suggesting future research directions in faster prefiltering and efficient geometry classification.

eytan
Télécharger la présentation

Raytracing Prefiltered Occlusion for Aggregate Geometry

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Raytracing Prefiltered Occlusion for Aggregate Geometry Lacewell, D., Burley, B., Boulos, S. and Shirley, P. IEEE Symposium on Interactive Raytracing, 2008

  2. Chasing Performance • Faster hardware • Faster single-ray intersection • Fewer samples • Importance sampling • Prefiltering

  3. Soft Shadows (2M tris) Standard, 4 rays Prefiltered, 9 rays Standard, 25 rays 112 seconds 74 seconds 704 seconds

  4. Bounding Volume Hierarchy - O(log N) ray intersection - O(N) update

  5. Early Ray Termination

  6. Early Termination (opaque boxes) Triangles Opaque boxes

  7. Bottom-up Prefiltering

  8. Bottom-Up Prefiltering

  9. Correlation Height

  10. Correlation Height

  11. Correlation Height

  12. Early Termination (opaque boxes) Triangles Opaque boxes

  13. Early Termination (prefiltered boxes) Triangles Prefiltered boxes

  14. Prefiltered (converged), 81 rays

  15. Regular, 81 rays, 3x slower

  16. Regular, 169 rays, 6x slower

  17. Variance Measurement

  18. Cost of Transparency

  19. Soft Shadows (5M tris) Standard, 9 rays Prefiltered, 9 rays Standard, 49 rays 64 seconds 87 seconds 339 seconds

  20. Ambient Occl. (3.8M triangles) Standard, 9 rays Prefiltered, 9 rays Standard, 36 rays 106 seconds 66 seconds 420 seconds

  21. When to Update? • Whenever BVH is updated • Independent of lights • No update for instances

  22. Memory Usage per Node

  23. Total Mem. Usage (GB) 3x3 Cubemap per Node

  24. Reference

  25. 3x3 Cubemap

  26. DC (average of 3x3 cubemap)

  27. DC (ortho average)

  28. Ad-hoc

  29. Reference

  30. 12x12 Cubemap

  31. DC (average of 12x12 cubemap)

  32. Conclusion • Simple to implement • Two runtime speedups: • Stop descending early • Less noise ==> Fewer rays • O(N) update • DC average often suffices

  33. Short-Term Future Work • Faster prefiltering • Quantization • Out of core scenes • Indirect diffuse

  34. Longer-Term Future Work Automatically classify geometry: • Nice mesh [Razor] • Aggregate and random [current paper] • Determine “correlation height” • Aggregate but not random [R-LOD?] • Buildings, vehicles, etc.

More Related