Abstract: A computer-animated scene is shaded using a point in a point cloud. The point represents a sample location on a surface primitive of an object in the scene. The surface primitive lies at least partially within a camera viewing frustum of a virtual camera, which has a focal point. A sample location distance, which is a near plane distance of the camera viewing frustum or the length of a line between the sample location on the surface primitive and the focal point of the virtual camera, is determined. A solid angle of the surface primitive subtended at the focal point of the virtual camera is obtained. A desired point area of the point in the point cloud is determined based on the sample location distance and the solid angle. The scene is shaded using the desired point area of the point in the point cloud.

Abstract: A technique for rendering an image of hair in a computer-generated scene is described. The scene includes a virtual light source and a hair virtual object comprising a material model. A hair shading function partly defining the material model is accessed. A set of random values is generated. The hair shading function is importance sampled by converting the set of random values into a set of light direction samples based on a Cauchy distribution. The probability density function of each converted light direction sample uses a Cauchy distribution. A light color value and a hair color value are computed for each light direction sample of the set of light direction samples. The light color values and the hair color values are weighted to determine a set of weighted values. A characteristic of a pixel representing part of the virtual object is determined based on the set of weighted values.

Abstract: A computer-animated scene is shaded by a computing system having an in-core memory and coupled to one or more out-of-core storage devices. The scene is comprised of shading locations on a surface element of an object in the scene. A point cloud representation of the scene is generated. An octree data structure based on the point cloud representation of the scene is generated. To generate the octree data structure, the Morton code for each point in the point cloud representation of the scene is computed. The points are then sorted based on the Morton code, recursively subdivided to find at most a threshold number of nodes, and written to the one or more out-of-core storage devices. The shading locations are then shaded based on the nodes written to the out-of-core storage devices.

Abstract: A high dynamic range (HDR) video can be compressed using inter-frame or intra-frame compression. The compression results in multiple encoded macroblocks and associated residual images. The residual images can be lossy compressed by mapping floating point image data values of the residual image from a light linear space to a perceptually linear space using a first non-linear mapping function. A value in the light linear space is proportionate to the power of a light source, and a value in the perceptually linear space is proportionate to a visual perceived brightness. Floating point discrete cosine transform (DCT) frequency coefficients of the floating point image data values of the residual image are determined. The floating point DCT frequency coefficients are quantized. The quantized floating point DCT frequency coefficients are compressed. The compression of the quantized floating point DCT frequency coefficients is lossless. The compressed quantized floating point DCT frequency coefficients are stored.

Abstract: A technique for rendering an image of hair in a computer-generated scene is described. The scene includes a virtual light source and a hair virtual object comprising a material model. A hair shading function partly defining the material model is accessed. A set of random values is generated. The hair shading function is importance sampled by converting the set of random values into a set of light direction samples based on a Cauchy distribution. The probability density function of each converted light direction sample uses a Cauchy distribution. A light color value and a hair color value are computed for each light direction sample of the set of light direction samples. The light color values and the hair color values are weighted to determine a set of weighted values. A characteristic of a pixel representing part of the virtual object is determined based on the set of weighted values.

Abstract: A method of rendering a scene with a plurality of objects includes rendering an object in a scene, wherein a portion of the object spans at least two of a plurality of non-overlapping tiles that subdivide the scene, and wherein the portion of the object is rendered only once in rendering the scene. The process further includes storing the rendered output of the object into a deep-framebuffer. While rendering the object and storing the rendered output of the object, in response to the size of the deep-framebuffer reaching a predetermined threshold, the steps that are performed include dividing the deep-framebuffer's contents based on the plurality of non-overlapping tiles, storing the divided contents of the deep-framebuffer in a plurality of tile files, and clearing the contents of the deep-framebuffer.

Abstract: A high dynamic range (HDR) image can be lossy compressed by first mapping floating point image data values of the HDR image from a light linear space to a perceptually linear space using a first non-linear mapping function. A value in the light linear space is proportionate to the power of a light source, and a value in the perceptually linear space is proportionate to a visual perceived brightness. Floating point discrete cosine transform (DCT) frequency coefficients of the floating point image data values of the HDR image are determined. The floating point DCT frequency coefficients are quantized. The quantized floating point DCT frequency coefficients are compressed. The compression of the quantized floating point DCT frequency coefficients is lossless. The compressed quantized floating point DCT frequency coefficients are stored.

Abstract: A computer-animated scene is shaded by a computing system having an in-core memory and coupled to one or more out-of-core storage devices. The scene is comprised of shading locations on a surface element of an object in the scene. A point cloud representation of the scene is generated. An octree data structure based on the point cloud representation of the scene is generated. To generate the octree data structure, the Morton code for each point in the point cloud representation of the scene is computed. The points are then sorted based on the Morton code, recursively subdivided to find at most a threshold number of nodes, and written to the one or more out-of-core storage devices. The shading locations are then shaded based on the nodes written to the out-of-core storage devices.

Abstract: Simulating dynamics (e.g., physical effects of inertia, forces, wind) on strands (e.g., hair) during computer based animation requires quick and accurate approximations of mathematical curves. Each strand is initially represented as a B-spline curve. Line segments approximating the curve are created by using affine combinations based on the curve's control vertices. Dynamics simulation is performed on the line segment approximation. Once an approximated strand is simulated, it is converted back into a B-spine curve representation for downstream processes, such as rendering. The rendering process displays the simulated strand to the animator.

Abstract: A computer-animated scene is shaded using a point in a point cloud. The point represents a sample location on a surface primitive of an object in the scene. The surface primitive lies at least partially within a camera viewing frustum of a virtual camera, which has a focal point. A sample location distance, which is a near plane distance of the camera viewing frustum or the length of a line between the sample location on the surface primitive and the focal point of the virtual camera, is determined. A solid angle of the surface primitive subtended at the focal point of the virtual camera is obtained. A desired point area of the point in the point cloud is determined based on the sample location distance and the solid angle. The scene is shaded using the desired point area of the point in the point cloud.

Abstract: A method and apparatus for high quality soft shadows for area lights in cinematic lighting for use in computer graphics, such as computer enabled animation. The method is an extension of traditional shadow maps, so the complexity of the present method is independent of geometric complexity. It uses multilayer translucent shadow maps, which can be used to produce high quality soft shadows for scenes with extremely complex geometry, fur, and volume objects. The present method computes the shadow factor by ray tracing the multilayer translucent shadow map.

Abstract: A method of rendering a scene with a plurality of objects includes rendering an object in a scene, wherein a portion of the object spans at least two of a plurality of non-overlapping tiles that subdivide the scene, and wherein the portion of the object is rendered only once in rendering the scene. The process further includes storing the rendered output of the object into a deep-framebuffer. While rendering the object and storing the rendered output of the object, in response to the size of the deep-framebuffer reaching a predetermined threshold, the steps that are performed include dividing the deep-framebuffer's contents based on the plurality of non-overlapping tiles, storing the divided contents of the deep-framebuffer in a plurality of tile files, and clearing the contents of the deep-framebuffer.

Abstract: A method of simulating a cloth includes: determining a first shape for the cloth at a first time; determining a first goal shape for the cloth at the first time; determining a first goal-directed force for the cloth at the first time from the first shape and the first goal shape, wherein the first goal directed force includes a component that measures a difference between the first shape and the first goal shape; and determining a second shape for the cloth at a second time from the first shape and the first goal-directed force by dynamically advancing the cloth from the first time to the second time.

Abstract: The present invention models hairs by generating hairs by interpolation and then further modifying the interpolated hairs to form clumps. The modified hairs can be iteratively reprocessed to generate more hairs and thereby produce a greater level of detail in the resulting hairstyle. The invention can be used to model any tubular structures protruding from a surface, such as strands of fur protruding from an animal's skin and blades of grass or stems of plants protruding from the ground.

Abstract: A posing system for three-dimensional characters and other models uses a stroke-based gestural language to position elements of the characters in a three-dimensional environment. A user draws a stroke in a two-dimensional interface in connection with a portion of model. The drawn stroke corresponds to an element of the model, such as a particular body part. A software program interprets the stroke and applies it to the placement or posing of the corresponding element. Additional elements are posed as necessary to further define the way in which the model as a whole should be posed. With a number of appropriate strokes for each of the elements, an animator can position the model in the scene.

Abstract: The present invention models hairs by generating hairs by interpolation and then further modifying the interpolated hairs to form clumps. The modified hairs can be iteratively reprocessed to generate more hairs and thereby produce a greater level of detail in the resulting hairstyle. The invention can be used to model any tubular structures protruding from a surface, such as strands of fur protruding from an animal's skin and blades of grass or stems of plants protruding from the ground.

Abstract: The present invention models hairs by generating hairs by interpolation and then further modifying the interpolated hairs to form clumps. The modified hairs can be iteratively reprocessed to generate more hairs and thereby produce a greater level of detail in the resulting hairstyle. The invention can be used to model any tubular structures protruding from a surface, such as strands of fur protruding from an animal's skin and blades of grass or stems of plants protruding from the ground.

Abstract: A compression system and method compresses three dimensional animation models. The system and method compresses an offset model, representative of a frame in an animation sequence with respect to a reference model from a reference frame of the sequence. The offset model is compressed by predicting the locations of offset vertices on the surfaces of the model based on the local geometry of reference vertices of the reference model. The offset vertex position is subtracted from the predicted position, and the difference is stored in a compressed data file. The prediction differences are easily compressed by any data compressor because the differences are generally small numbers.

Abstract: A posing system for three-dimensional characters and other models uses a stroke-based gestural language to position elements of the characters in a three-dimensional environment. A user draws a stroke in a two-dimensional interface in connection with a portion of model. The drawn stroke corresponds to an element of the model, such as a particular body part. A software program interprets the stroke and applies it to the placement or posing of the corresponding element. Additional elements are posed as necessary to further define the way in which the model as a whole should be posed. With a number of appropriate strokes for each of the elements, an animator can position the model in the scene.

Abstract: A method of simulating a cloth includes: determining a first shape for the cloth at a first time; determining a first goal shape for the cloth at the first time; determining a first goal-directed force for the cloth at the first time from the first shape and the first goal shape, wherein the first goal directed force includes a component that measures a difference between the first shape and the first goal shape; and determining a second shape for the cloth at a second time from the first shape and the first goal-directed force by dynamically advancing the cloth from the first time to the second time.