Visibility-based environment importance sampling for light transport simulation systems and applications
AssigneeNVIDIA Corporation
InventorsPascal Gautron, Carsten Waechter
Life of this patent
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Abstract
Systems and methods to implement a technique for determining an environment importance sampling function. An environment map may be provided where lighting information about the environment is known, but where certain pixels within a scene associated with the environment map are shaded. From these shaded pixels, rays may be drawn in random directions to determine whether the rays are occluded or can interact with the environment map, which provides an indication of a source of lighting that can be used for light transport simulations. A mask may be generated based on these occlusions and used to update the environment importance sampling function.
Claims20
A system, comprising:
- one or more processing units to:
- trace one or more respective rays from a plurality of scene locations of a scene represented using an environment map that includes one or more features corresponding to lighting information;
- determine one or more respective interaction locations for the one or more respective rays with respect to the environment map;
- identify at least one respective interaction location of the one or more respective interaction locations as an occlusion;
- generate a mask for the environment map based at least on the at least one respective interaction location identified as the occlusion, the mask indicating that the at least one respective interaction location corresponds to the occlusion;
- and
- generate, based at least on the mask, an importance sampling function.
A method, comprising:
- generating an importance sampling function using an environment map intensity;
- allocating a mask for the environment map;
- determining, for at least one rendering iteration, a first set of one or more random directions from at least one shaded point by importance sampling a reflectance function of a surface at the at least one shaded point;
- tracing a first ray for at least one direction of the first set of one or more random directions and marking the corresponding environment map pixel when the first ray is unoccluded;
- determining a second set of one or more random directions from the at least one shaded point by importance sampling the environment map using the importance sampling function;
- tracing a second ray for at least one direction of the second set of random directions and marking the corresponding environment map pixel when the second ray is unoccluded;
- applying multiple importance sampling to combine contributions using one or more rays traced from the first and second sets of one or more random directions and to generate an incoming radiance estimate for the at least one shaded point;
- and
- updating the importance sampling function using one or more of the marked environment map pixels.
A processor comprising:
- one or more processing units to:
- generate an initial importance sampling function based at least on an environment map corresponding to a frame to be rendered;
- trace, based at least on the initial importance sampling function, one or more rays corresponding to at least one pixel in the frame;
- determine an occlusion status for at least one respective ray of the one or more rays with respect to the environment map;
- and
- generate a mask corresponding to the environment map, the environment map indicating the respective occlusion status of the at least one respective ray.
Dependencies are inferred from the claim text.