Ray-tracing with irradiance caches
Disclosed approaches provide for irradiance caches which may be used to share irradiance between ray interactions spatially and/or temporally. An irradiance cache may store incoming irradiance or outgoing irradiance and may be updated by casting one or more rays from one or more locations to sample irradiance for the location(s). The number of rays that are cast may be reduced by ranking the locations, irradiance caches, and/or corresponding groups of geometry based on one or more characteristics thereof. For example, a ranking score may be computed based on camera distance, camera visibility, and/or a number of frames since a prior update. When sampling a location, outgoing irradiance from an outgoing irradiance cache may be used to determine shading when a hit distance of a ray used to generate the sample exceeds a threshold value.
1. A method comprising:
ranking at least one first location of a plurality of locations in a virtual environment against at least one second location of the plurality of locations based at least on one or more characteristics of the at least one first location and the at least one second location, each location of at least the first and second locations being associated with one or more irradiance caches to store irradiance that corresponds to the location;
casting a ray from the at least one first location based at least on the at least one first location having a higher ranking than the at least one second location;
determining at least one irradiance value that corresponds to an interaction of the ray in the virtual environment; and
rendering, based at least on the interaction, a frame of the virtual environment using at least the irradiance from the one or more irradiance caches associated with the first location and the at least one irradiance value.
2. The method of claim 1 , wherein the irradiance stored at the one more irradiance caches is the irradiance at the location.
3. The method of claim 1 , further comprising selecting the at least one first location from the locations for the casting based at least on the ranking and a budget that defines a number of rays that are cast from the locations to perform the rendering.
4. The method of claim 1 , wherein each location of the locations is a vertex of a polygon mesh corresponding to a three-dimensional object.
5. The method of claim 1 , wherein the rendering of the frame comprises shading one or more portions of the virtual environment using the irradiance from the one or more irradiance caches associated with the at least one first location and the irradiance from the one or more irradiance caches associated with the at least one second location.
6. The method of claim 1 , wherein the ranking comprises ranking geometry groups that include subsets of the locations based at least on one or more characteristics of the geometry groups.
7. The method of claim 1 , wherein the one or more characteristics are based at least on a distance between the location and a virtual camera in the virtual environment.
8. The method of claim 1 , wherein the one or more characteristics are based at least on a visibility of the location with respect to a virtual camera in the virtual environment.
9. The method of claim 1 , wherein the one or more characteristics are based at least on a number of frames since a prior update to the one or more irradiance caches associated with the location.
10. A method comprising:
selecting at least one group of geometries in a virtual environment based at least on one or more first locations within the at least one group being ranked higher than one or more second locations in the virtual environment in a ranking based at least on one or more characteristics of the one or more first locations and the one or more second locations, the at least one group comprising irradiance caches to store irradiance of the one or more first locations within the group;
casting one or more rays from the one or more first locations based at least on the selecting of the at least one group;
updating at least one of the irradiance caches based at least on one or more interactions of the one or more rays in the virtual environment; and
rendering a frame of the virtual environment using one or more of the irradiance caches.
11. The method of claim 10 , wherein the selecting includes selecting a subset of groups of geometries of the virtual environment using the ranking and a budget that defines a number of rays that are cast from the groups of geometries to perform the rendering.
12. The method of claim 10 , wherein the one or more characteristics are based at least on a distance of at least a portion of the at least one group from a virtual camera in the virtual environment.
13. The method of claim 10 , wherein the one or more characteristics are based at least on a visibility of at least a portion of the at least one group with respect to a virtual camera in the virtual environment.
14. The method of claim 10 , wherein the one or more characteristics are based at least on a number of frames since a prior update to one or more of the irradiance caches of the at least one group.
15. The method of claim 10 , wherein the rendering comprises applying a denoising filter to a pixel using one or more irradiance values from the one or more of the irradiance caches to determine a value of a pixel based at least on detecting a disocclusion of the pixel.
16. A method comprising:
casting a ray from a first location in a virtual environment;
determining an interaction of the ray with a second location in the virtual environment, the second location associated with an outgoing irradiance cache that stores outgoing irradiance corresponding to the second location; and
rendering a frame of the virtual environment using the outgoing irradiance from the outgoing irradiance cache based at least on a distance between the first location and the second location.
17. The method of claim 16 , wherein the rendering of the frame includes shading the first location using the outgoing irradiance from the outgoing irradiance cache.
18. The method of claim 16 , wherein the rendering uses the outgoing irradiance based at least on the distance being greater than a threshold value.
19. The method of claim 16 , wherein the rendering includes applying a denoising filter to a pixel using the outgoing irradiance based at least on detecting a disocclusion of the pixel.
20. The method of claim 16 , wherein the method further comprises updating an outgoing irradiance cache that stores outgoing irradiance corresponding to the first location using the outgoing irradiance corresponding to the second location.