Abstract: There is provided a method for ray-mediated illumination control. The method includes identifying a first activation region corresponding to one of an origin and a destination of a ray, where the ray is described by a ray data associated with the ray. The method further includes identifying a second activation region corresponding to the other one of the origin and the destination of the ray, interpreting an illumination rule for the ray based on at least one of the first activation region and the second activation region, and modifying an illumination in one of the first activation region and the second activation region based on the illumination rule and the ray data.

Abstract: The disclosure provides an approach for simulating and rendering materials across different states and undergoing phase transitions. In one configuration, a simulation application generates video frames depicting a material phenomenon using an augmented material point method (MPM). Traditional MPM does not handle incompressible materials such as fluids. Techniques disclosed herein augment the MPM with a Chorin-style projection technique to enable simulation of arbitrarily incompressible materials. In one configuration, this is achieved with a marker-and-cell (MAC) grid based MPM solver, a splitting of stress used in the simulation into elastic and dilational parts, a projection-like implicit treatment of the Eulerian evolution of the dilational part of the stress, and particular techniques for rasterizing and updating quantities on the MAC grid. In addition, a heat model may be coupled to the MPM solver, allowing material changes to be driven with temperature and phase changes.

Abstract: The disclosure provides an approach for simulating and rendering granular materials. A simulation application generates video frames depicting a granular material phenomenon using a strain based elasto-plastic constitutive model integrated with a hybrid Eulerian/Lagrangian material point method (MPM). The elasto-plastic constitutive model includes physical equation(s) which dictate forces that affect the granular material during the simulation. In particular, the constitutive model may include user-controllable parameters defining threshold(s) to start plastic deformation, as well as a hardening parameter which controls how fast the granular material packs under compression. The MPM is a procedure in which particles of the granular material and a background grid are coupled, with the grid being used to assist in computing forces dictated by the physical equation(s) of the elasto-plastic constitutive model.

Abstract: There is provided a system including a memory storing a software application and a processor configured to execute the software application to transmit a light through a scene, the scene including a medium described by an extinction function, define a fictitious medium described by a fictitious extinction function, determine a path through the medium, the path including a plurality of points, calculate one of a plurality of weights for each of the plurality of points, the one of the plurality of weights corresponding to one minus the ratio of the extinction function to the fictitious extinction function, and estimate a transmittance of the lights through the medium as a product of the plurality of weights.

Abstract: The disclosure provides an approach for rendering images which include subsurface scattering effects. In one aspect, a shader computes subsurface scattering effects via a ray-tracing or point-based technique using a normalized diffusion profile. The shader may use the inverse of a cumulative density function associated with the normalized diffusion profile to determine, for each ray intersecting the surface, points on the surface at which to evaluate the normalized diffusion profile. To determine the lit surface of a pixel due to subsurface scattering, the shader may multiply the result of the integral of the normalized diffusion profile for each of the R, G, and B color components by corresponding components of a diffuse color constant. Further, the shader may scale the integral of the normalized diffusion profile based on a scaling function which accounts for a forward-scattering nature of a medium and compensates for out-of-plane scattering.

Abstract: There is provided a system and a method for ordering rays in rendered graphics for coherent shading. The method comprises recording, using the processor, intersection points for each of a plurality of directional queries in the memory, wherein each of the plurality of directional queries has one intersection point, organizing, using the processor, the intersection points in the memory into a plurality of elements, and grouping, using the processor, the intersection points in the memory by shading context. The method may further comprise shading the intersection points, wherein the shading is performed on a plurality of elements substantially concurrently. The shading context may include a volume of intersection points. In another implementation, the shading context may be one of texture ID, material ID, and element ID. Additionally, the texture ID may correspond to a mesh face ID.

Abstract: There is provided a system including a memory storing a software application and a processor configured to execute the software application to transmit a light through a scene, the scene including a medium described by an extinction function, define a fictitious medium described by a fictitious extinction function, determine a path through the medium, the path including a plurality of points, calculate one of a plurality of weights for each of the plurality of points, the one of the plurality of weights corresponding to one minus the ratio of the extinction function to the fictitious extinction function, and estimate a transmittance of the lights through the medium as a product of the plurality of weights.

Abstract: A novel algorithmic framework is presented for the simulation of hyperelastic soft tissues that drastically improves each aspect discussed above compared to existing techniques. The approach is robust to large deformation (even inverted configurations) and extremely stable by virtue of careful treatment of linearization. Additionally, a new multigrid approach is presented to efficiently support hundreds of thousands of degrees of freedom (rather than the few thousands typical of existing techniques) in a production environment. Furthermore, these performance and robustness improvements are guaranteed in the presence of both collision and quasistatic/implicit time stepping techniques. The result is a significant advance in the applicability of hyperelastic simulation to skeleton driven character skinning.

Abstract: A method is provided for integration cone tracing with particular application for feature films and other demanding content creation using scenes of high complexity requiring global illumination. Instead of using a conventional noise prone ray tracer, cones are intersected with a scene bounding hierarchy to determine intersecting scene geometry, and integration results are computed by directional sampling within the cones. As a result, the working data set may be reduced as the rendering may begin with a smaller set of cones as compared to the large number of rays required for acceptable filtering in a conventional ray tracer. Furthermore, by refining the cones during the rendering only on an as-needed basis according to an acceptable noise threshold and by sharing secondary cone bounces among primary cones, the processing workload and data set requirements may be kept to a reasonable level even for multiple global illumination passes.

Abstract: A method is provided for distributed element rendering with particular application for feature films and other demanding content creation using scenes of high complexity requiring global illumination. A persistent centralized scheduler receives shading queries that are added to a request queue, determines an assignment of the request queue to hardware resources based on a resource map, and processes the request queue according to the assignment to render frames of one or more scenes. The resource map may be built by the scheduler and indicates local scene geometry cached for each of the hardware resources. By generating a full set of camera rays at each hardware resource, global illumination shading and other rendering can proceed independently against local geometry caches for high parallelism. Redundant computations are reduced through the scheduler, which may cache frequently requested rendering results including tessellation, shading, and level of detail.

Abstract: The disclosure provides an approach for simulating and rendering granular materials. A simulation application generates video frames depicting a granular material phenomenon using a strain based elasto-plastic constitutive model integrated with a hybrid Eulerian/Lagrangian material point method (MPM). The elasto-plastic constitutive model includes physical equation(s) which dictate forces that affect the granular material during the simulation. In particular, the constitutive model may include user-controllable parameters defining threshold(s) to start plastic deformation, as well as a hardening parameter which controls how fast the granular material packs under compression. The MPM is a procedure in which particles of the granular material and a background grid are coupled, with the grid being used to assist in computing forces dictated by the physical equation(s) of the elasto-plastic constitutive model.

Abstract: The disclosure provides an approach for simulating and rendering materials across different states and undergoing phase transitions. In one configuration, a simulation application generates video frames depicting a material phenomenon using an augmented material point method (MPM). Traditional MPM does not handle incompressible materials such as fluids. Techniques disclosed herein augment the MPM with a Chorin-style projection technique to enable simulation of arbitrarily incompressible materials. In one configuration, this is achieved with a marker-and-cell (MAC) grid based MPM solver, a splitting of stress used in the simulation into elastic and dilational parts, a projection-like implicit treatment of the Eulerian evolution of the dilational part of the stress, and particular techniques for rasterizing and updating quantities on the MAC grid. In addition, a heat model may be coupled to the MPM solver, allowing material changes to be driven with temperature and phase changes.

Abstract: Some aspects of the disclosure include systems and methods for grouping rays into sets according to their directions. In some cases, the rays of the directional sets may then be organized into a hierarchy according to their origins and bounding cones are generated for the hierarchy nodes. The resulting bounding cone hierarchy may be intersected with a bounding volume hierarchy or other scene hierarchy.

Abstract: A method is provided for streaming light propagation with particular application for feature films and other demanding content creation using scenes of high complexity requiring art directed global illumination. By attaching a data recording shader or equivalent functionality to any tracing based renderer that can provide multi-pass global illumination, the complete set of light bounce propagation records and the set of emissive samples for a particular rendering can be recorded to memory or disk. A user may edit the emissive samples to adjust the lighting environment, including modifying light source color and intensity and even moving and adding new emissive samples. To relight the scene, the edited emissive samples are processed through the propagation records using a streaming multiply-and-add operation amenable to high levels of parallelization, avoiding a costly re-rendering of the scene and providing a final quality result in interactive time.

Abstract: A method is provided for a streaming hierarchy traversal renderer with particular application for feature films and other demanding content creation using scenes of high complexity that cannot fit in memory. The renderer organizes scene geometry into a spatial hierarchy, generates directional queries to be traced in the spatial hierarchy, performs a streaming hierarchy traversal over the directional queries, and uses the results of the directional queries to shade or render the scene. The traversal performs a single pass over the directional queries for splitting into one child stream of directional queries for each child node at each scene node in the hierarchy. A prioritized traversal of the hierarchy may also be carried out using various cost-metrics for optimized parallelism. The rendering may also bounce the directional queries to provide multi-pass global illumination.

Abstract: There is provided a method for ray-mediated illumination control. The method includes identifying a first activation region corresponding to one of an origin and a destination of a ray, where the ray is described by a ray data associated with the ray. The method further includes identifying a second activation region corresponding to the other one of the origin and the destination of the ray, interpreting an illumination rule for the ray based on at least one of the first activation region and the second activation region, and modifying an illumination in one of the first activation region and the second activation region based on the illumination rule and the ray data.

Abstract: The disclosure provides an approach for rendering images which include subsurface scattering effects. In one aspect, a shader computes subsurface scattering effects via a ray-tracing or point-based technique using a normalized diffusion profile. The shader may use the inverse of a cumulative density function associated with the normalized diffusion profile to determine, for each ray intersecting the surface, points on the surface at which to evaluate the normalized diffusion profile. To determine the lit surface of a pixel due to subsurface scattering, the shader may multiply the result of the integral of the normalized diffusion profile for each of the R, G, and B color components by corresponding components of a diffuse color constant. Further, the shader may scale the integral of the normalized diffusion profile based on a scaling function which accounts for a forward-scattering nature of a medium and compensates for out-of-plane scattering.

Abstract: There is provided a system and a method for ordering rays in rendered graphics for coherent shading. The method comprises recording, using the processor, intersection points for each of a plurality of directional queries in the memory, wherein each of the plurality of directional queries has one intersection point, organizing, using the processor, the intersection points in the memory into a plurality of elements, and grouping, using the processor, the intersection points in the memory by shading context. The method may further comprise shading the intersection points, wherein the shading is performed on a plurality of elements substantially concurrently. The shading context may include a volume of intersection points. In another implementation, the shading context may be one of texture ID, material ID, and element ID. Additionally, the texture ID may correspond to a mesh face ID.

Abstract: A computer graphic system and methods for simulating hair is provided. In accordance with aspects of the disclosure a method for hybrid hair simulation using a computer graphics system is provided. The method includes generating a plurality of modeled hair strands using a processor of the computer graphics system. Each hair strand includes a plurality of particles and a plurality of spring members coupled in between the plurality of particles. The method also includes determining a first position and a first velocity for each particle in the plurality of modeled hair strands using the processor and coarsely modeling movement of the plurality of modeled hair strands with a continuum fluid solver. Self-collisions of the plurality of modeled hair strands are computed with a discrete collision model using the processor.

Abstract: A method is provided for distributed element rendering with particular application for feature films and other demanding content creation using scenes of high complexity requiring global illumination. A persistent centralized scheduler receives shading queries that are added to a request queue, determines an assignment of the request queue to hardware resources based on a resource map, and processes the request queue according to the assignment to render frames of one or more scenes. The resource map may be built by the scheduler and indicates local scene geometry cached for each of the hardware resources. By generating a full set of camera rays at each hardware resource, global illumination shading and other rendering can proceed independently against local geometry caches for high parallelism. Redundant computations are reduced through the scheduler, which may cache frequently requested rendering results including tessellation, shading, and level of detail.