SYSTEM, METHOD, AND COMPUTER PROGRAM PRODUCT FOR PERFORMING PATH SPACE FILTERING

• US 20140313198A1
• Filed: 01/28/2014
• Published: 10/23/2014
• Est. Priority Date: 04/22/2013
• Status: Active Grant

• Current Assignee: NVIDIA Corporation
• Original Assignee: NVIDIA Corporation
• Inventors: Keller, Alexander, Binder, Nikolaus, Dahm, Ken Patrik
• Granted Patent: US 9,953,457 B2
• Time in Patent Office: Days
• US Class Current: 345/426
• CPC Class Codes: G06T 15/06 Ray-tracing
• CPC Class Codes: G06T 15/506 Illumination models

Abstract

A system, method, and computer program product are provided for performing path space filtering. In use, a set of light transport paths associated with a scene is sampled. Additionally, a plurality of vertices associated with the sampled set of light transport paths is selected, where each selected vertex has an associated throughput and light contribution. Further, an averaged light contribution of each of the selected plurality of vertices is determined, utilizing one or more weights. Further still, the averaged light contribution of each of the selected plurality of vertices is combined after multiplying the averaged light contribution of each of the selected vertices by the associated throughput of the vertex.

Claims

1. A method, comprising:

sampling a set of light transport paths associated with a scene;

selecting a plurality of vertices associated with the sampled set of light transport paths, where each selected vertex has an associated throughput and light contribution;

determining an averaged light contribution of each of the selected plurality of vertices, utilizing one or more weights; and

combining the averaged light contribution of each of the selected plurality of vertices after multiplying the averaged light contribution of each of the selected vertices by the associated throughput of the vertex.

2. The method of claim 1, further comprising repeating the selecting, determining, and combining in an iterative manner.

3. The method of claim 1, further comprising locally filtering the sampled set of light transport paths.

4. The method of claim 3, wherein the filtering is performed before the determining of the averaged light contribution of each of the selected plurality of vertices.

5. The method of claim 3, wherein one or more of a random, pseudo-random, or quasi-random selection of the samples to be filtered is performed.

6. The method of claim 3, wherein the local filtering improves an efficiency of a numerical integro-approximation.

7. The method of claim 3, wherein combining the averaged light contribution of each of the selected plurality of vertices is performed during a light transport simulation, and the local filtering improves an efficiency of the light transport simulation.

8. The method of claim 1, wherein the set of light transport paths is sampled by one or more of generating eye paths, generating light paths, and connecting one or more eye paths and light paths by one or more of shadow rays and proximity.

9. The method of claim 1, wherein the method is implemented as a progressive method.

10. The method of claim 1, further comprising, for the i-th light transport path within the sampled set of light transport paths, storing at least one vertex x_i, an attenuation α

_i along an eye path segment to the vertex x_i, and a radiance contribution c, of a light path segment to the vertex x_i.

11. The method of claim 10, further comprising forming an image by accumulating α

_i·

c_i, where

12. The method of claim 11, wherein has a radius r(n) around the vertex x_i.

13. The method of claim 12, wherein

14. The method of claim 1, wherein the plurality of vertices are selected utilizing a range search.

15. The method of claim 14, wherein the range search is performed by at least one of a hash grid, a classic range search, and a divide-and-conquer method.

16. The method of claim 12, wherein the radius r(n) is chosen by at least one of a distance along a path or a solid angle.

17. The method of claim 16, wherein each of the one or more weights measure a similarity between one or more of the selected plurality of vertices, where such similarity depends on one or more of a geometric similarity, a transport similarity, and a visibility similarity between one or more of the selected plurality of vertices.

18. The method of claim 1, wherein the method is applied across multiple views for one or more of rendering stereo image pairs, rendering multiple frames in an animation, and rendering a set of images required for one or more light field displays.

19. The method of claim 1, further comprising simulating motion blur by averaging one or more images at one or more distinct points in time.

20. The method of claim 1, wherein sampling the set of light transport paths is decoupled from one or more shading operations.

21. The method of claim 3, wherein locally filtering the sampled set of light transport paths is performed linearly and is applied on top of a sampling based rendering engine.

22. The method of claim 1, wherein the sampling a set of light transport paths is performed by one or more of a random, pseudo-random, or quasi-random sampling.

23. The method of claim 10, further comprising averaging the radiance contribution c_i with an associated wavelength λ

_i to consistently simulate spectral light transport.

24. The method of claim 1, wherein the light transport paths include light transport paths with vertices in one or more of participating media and translucent matter.

25. The method of claim 1, wherein the determining of an averaged light contribution of each of the selected plurality of vertices, utilizing one or more weights, is iterated.

26. A non-transitory computer-readable storage medium storing instructions that, when executed by a processor, cause the processor to perform steps comprising:

sampling a set of light transport paths associated with a scene;

selecting a plurality of vertices associated with the sampled set of light transport paths, where each selected vertex has an associated throughput and light contribution;

determining an averaged light contribution of each of the selected plurality of vertices, utilizing one or more weights; and

combining the averaged light contribution of each of the selected plurality of vertices after multiplying the averaged light contribution of each of the selected vertices by the associated throughput of the vertex.

27. A system, comprising:

a processor for;

sampling a set of light transport paths associated with a scene;

selecting a plurality of vertices associated with the sampled set of light transport paths, where each selected vertex has an associated throughput and light contribution;

determining an averaged light contribution of each of the selected plurality of vertices, utilizing one or more weights; and

combining the averaged light contribution of each of the selected plurality of vertices after multiplying the averaged light contribution of each of the selected vertices by the associated throughput of the vertex.