Nvidia Corporation

Jakub Boksansky

Oliver Mark Wright

Tomas G Akenine-Moller

Tomas Akenine-Moller

Oli Wright

Christopher Ryan Wyman

Chris Wyman

Paula Eveliina Jukarainen

Approaches in accordance with various illustrative embodiments provide for the selection and reuse of lighting sample data to generate high quality initial candidates, suitable for input to resampling techniques, that are better representative of the actual lighting of a scene for which an image, video frame, or other such representation is to be rendered. Instead of discarding an important light samples where weight or sample count may no longer be reliable, at least some of these samples can be provided as additional, unweighted candidates for use in importance sampling, in addition to those selected using a random (or semi-random) sampling process. Such an approach can help to ensure that important lights are considered when shading pixels for a scene, at least where such reuse makes sense due to changes in scene or location. Samples reused between frames can relate to various prior samples, such as samples that were determined to correspond to important, close, or bright lights.

Initial candidates in spatiotemporal resampling

Devices, systems, and techniques to incorporate lighting effects into computer-generated graphics. In at least one embodiment, a virtual scene comprising a plurality of lights is rendered by subdividing the virtual area and stored, in a record corresponding to a subdivision of the virtual area, information indicative of one or more lights in the virtual area selected based on a stochastic model. Pixels near a subdivision are rendered based on the light information stored in the subdivision.

Grid-based light sampling for ray tracing applications

One embodiment of a method rendering one or more graphics images includes tracing a ray cone through a three-dimensional (3D) graphics scene, generating a refracted ray cone based on the ray cone and a two-dimensional (2D) coordinate frame, and rendering a graphics image based on the refracted ray cone.

Techniques for texture filtering using refracted ray cones

In various examples, a virtual light meter may be implemented along with ray tracing techniques in order to determine incident light values—e.g., incoming irradiance, incident radiance, etc.—for adjusting auto exposure values of rendered frames. For example, one or more rays may be used to sample incident light over a sampling pattern—such as a hemispherical sampling pattern—for any position in a virtual game environment. As a result, the incident light values may be sampled near a subject of interest in a scene or frame such that exposure values are consistent or stable regardless of the composition of the rendered frames.

Ray-tracing for auto exposure

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.

Ray-tracing with irradiance caches

One embodiment of a method for computing a texture color includes tracing a ray cone through a graphics scene, determining a curvature of a first surface within the graphics scene at a point where the ray cone hits the first surface based on differential barycentric coordinates associated with the point, determining, based on the curvature of the first surface, a width of the ray cone at a subsequent point where the ray cone hits a second surface within the graphics scene, and computing a texture color based on the width of the ray cone.

Techniques for ray cone tracing and texture filtering

One embodiment of a method for computing a texture color includes tracing a ray cone through a graphics scene, determining at least one axis of an ellipse formed by the ray cone intersecting a plane associated with geometry within the graphics scene at a hit point, computing one or more gradients along the at least one axis of the ellipse, and computing a texture color based on the one or more gradients and a texture.

Techniques for anisotropic texture filtering using ray cones

In various examples, a virtual light meter may be implemented along with ray tracing techniques in order to determine incident light values&#x2014;e.g., incoming irradiance, incident radiance, etc.&#x2014;for adjusting auto exposure values of rendered frames. For example, one or more rays may be used to sample incident light over a sampling pattern&#x2014;such as a hemispherical sampling pattern&#x2014;for any position in a virtual game environment. As a result, the incident light values may be sampled near a subject of interest in a scene or frame such that exposure values are consistent or stable regardless of the composition of the rendered frames.

Growing community of inventors

Munich, Germany

Jakub Boksansky