1 / 34

Precomputed Shadow Fields for Dynamic Scenes

Microsoft Research Asia. Precomputed Shadow Fields for Dynamic Scenes. Kun Zhou Yaohua Hu Stephen Lin Baining Guo Heung-Yeung Shum. 1. Outline. • Introduction • Method Overview • Detail • Results. • Introduction • Method Overview • Detail • Results. Introduction. Soft Shadow:

coen
Download Presentation

Precomputed Shadow Fields for Dynamic Scenes

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. Microsoft Research Asia Precomputed Shadow Fields for Dynamic Scenes Kun Zhou Yaohua Hu Stephen Lin Baining Guo Heung-Yeung Shum 1

  2. Outline • Introduction • Method Overview •Detail • Results

  3. • Introduction • Method Overview • Detail • Results

  4. Introduction Soft Shadow: multiple shadow maps -[Heckbert and Herf] 1997 Exntnd shadow volume -[Assarsson and Akenine-Moller] 2003 Fake approach -[Chan and Durand] 2003

  5. Introduction Why this is not good? For a dynamic scene: -scene complexity -recomputed for each frame For illuminants: -point-like or small light source 5

  6. Introduction PRT (Precomputed Radiance Transfer): based on two main assumptions: 1.all objects in the scene are non-emitters 2.the incoming light direction is independent with the position of a point x 6

  7. Introduction PRT (Precomputed Radiance Transfer): These spherical functions can be compressed by using some basis functions: Spherical harmonics Wavelet 7

  8. Introduction 8

  9. • Introduction • Method Overview • Detail • Results

  10. Method Overview 10

  11. Method Overview Compute Incoming radiance of each point 11

  12. Method Overview Compute Occlusion Field for each Object 12

  13. Method Overview Compute Occlusion Field for each Object 13

  14. Method Overview Compute Occlusion Field for each Object 14

  15. Method Overview Compute Occlusion Field for each Object 15

  16. Method Overview Compute radiance field for each Light Source 16

  17. Method Overview Compute Radiance Field for each Light Source 17

  18. Method Overview multiply these and self-visibility at the point together => Incident radiance distribution 18

  19. Method Overview Combine with the BRDF to get the final radiance at the point 19

  20. Method Overview Combine with the BRDF to get the final radiance at the point 20

  21. • Introduction • Method Overview •Detail • Results

  22. Detail SRF and OOF Precomputation 22

  23. Detail Data Sampling For low frequency shadow: 16 concentric spheres For all frequency shadow: 32 concentric spheres Intermediate points: trilinear interpolation with 8 nearest samples 23

  24. Detail Data Compression How? approximate the function using basis functions 24

  25. Detail Data Compression For low frequency shadow: Spherical harmonics 25

  26. Detail Data Compression Spherical harmonics reconstruction 26

  27. Detail Data Compression Spherical harmonics has two properties: 1.Rotationaly invariant 2.Integrating the product of two SH functions = a dot product of their coefficients. 27

  28. Detail Data Compression For all frequency shadow: Wavelet Basis 28

  29. Detail Data Compression Spherical harmonics VS Wavelet 29

  30. Detail Incident Radiance Computation 30

  31. Detail Soft Shadow Rendering Acceleration -Culling -Lazy Occlusion Updating occluders for a specific light source remain unchanged, the cached visibility can be reused 31

  32. • Introduction • Method Overview • Detail • Results

  33. Results

  34. Thank You !

More Related