Pixar

Light Source Computer Images, Inc.

Pixar Animation Studios

Robert L Cook

Thomas Douglas Selkirk Duff

Loren C Carpenter

Thomas K Porter

John R Anderson

Edward M Granger

Eric M Herrmann

Lawrence D Baca

Akin Dirik

Nelson Offner

Andrew Witkin

Tony DeRose

Peter-Pike Sloan

Manuel Kraemer

Brian Smits

Pitchaya Sitthi-Amorn

Surfaces without a global surface coordinate system are divided into surface regions having local surface coordinate systems to enable the caching of surface attribute values. A surface attribute value for a surface region may include contributions from two or more adjacent surfaces. Sample points may be arranged at the corners, rather than centers, of surface regions and include prefiltered values based on two or more surfaces. A renderer may sample the surface attribute function using these prefiltered values without accessing any adjacent surfaces, even if the renderer's filter crosses a surface boundary. A multiresolution cache stores surface attribute values at different resolution levels for surface regions of one or more surfaces, which may be discontiguous. Two or more resolution levels may have the same number of sample points but have values based on filters with different areas and spatial frequency limits. Resolution levels may be selected based on geodesic distance on a surface.

Caching attributes of surfaces without global parameterizations

A method for a computer system for inspecting an animation sequence having a series of specified poses of an animated character includes receiving a mathematical performance style model associated with the animated character, receiving the series of specified poses of the animated character, each specified pose comprising respective values for the plurality of animation variables, determining an associated quality factor for each specified pose in response to the respective values for the plurality of animation variables and in response to the mathematical performance style model associated with the animated character, and providing feedback to a user in response to an associated quality factor for at least one specified pose.

Methods and apparatus for performance style extraction for quality control of animation

Adaptive sampling alleviates aliasing by partitioning the field of view of an image sample point into depth regions. Portions of the scene are sampled within a depth region using sample rays. If a sample ray is not completely occluded in the depth region, corresponding sample rays are evaluated in adjacent depth regions. Sample rays can be recursively evaluated in further depth regions until all the subsamples intersect opaque objects or a depth limit or transparency threshold is reached. The value of an image sample point is the weighted combination of sample rays. The number of sample rays in each depth region may increase monotonically with distance along a line of sight from an image sample point for effects such as reflection, refraction, and illumination. The number of sample rays in each depth region may increase monotonically with distance from a focal plane for effects such as depth of field.

Adaptive depth of field sampling

An image may be represented by a directed acyclic graph (DAG) including a number of nodes on paths between input parameters and output values. Intermediate operations are performed at the nodes to produce intermediate output values. One or more of the input parameters may be modified (e.g., by an animator). A determination is then made as to which intermediate output values are affected by the modified input parameters. A simplified DAG is constructed from the nodes corresponding to the intermediate output values affected by the modified input parameters. The intermediate output values that are not affected by the modified input parameters and are maintained at a constant value corresponding to a previously determined value for the intermediate output value. The simplified DAG is evaluated to determine the output resulting from the modified input parameter such that the image may be re-rendered without re-evaluating the full DAG.

Re-rendering a portion of an image

A degree of detail calculation required for calculations to process computer graphics data is determined based on input parameters that are varying in certain dimensions. During a detail analysis of a shader, a directed graph is built in such a way that each connection between nodes indicates a dependency among inputs and outputs of calculations and/or input parameters. For each input parameter, variability information about the input parameter is obtained. A lattice or a table representing dimensional variability is used to determine a variability value for each calculation for given input parameters and dependency relationships among other calculations. After a variability value has been determined for each calculation, calculations are grouped into several groups and executed once per the variability value.

System and method for generating computer graphic images by identifying variant and invariant shader arguments

A shader can include a series of instructions, among which are horizontal instructions and vertical instructions. Executing such shader for rendering animation information may mean many redundant computations on millions of graphic data points. Thus, vertical instructions are separated out from horizontal instructions and executed in a vertical manner, thereby reducing rendering time and cache space used during the process. That is, a block of instructions is recursively subdivided until a number of instructions that are to be executed in a horizontal manner are approximately minimized in each sub-block. All of the identified vertical sub-blocks can process each data point individually and independently from other data points, thereby achieving various advantages, including, but not limited to, temporary processing, index processing, efficient caching and the like.

Systems and methods for mixing the execution order of shading language code

An ordered object list is compared with an ordered ray list and if the coordinate value of an entry in the ray list is less than the coordinate value of an entry in the object list, then the ray is added to an active ray list, and a trace of that ray is made against all objects in an active object list. If the coordinate value of the entry in the ray list is greater than the coordinate value of the entry in the object list, then the coordinate value corresponding to the entry in the object list is added to an active object list, and a trace of all rays in the active ray list is made against that coordinate value. Rays and objects are removed from the active lists based on determinations as to whether a trace hit occurred and/or which object point is encountered.

Streamed ray tracing system and method

A method for rendering an image including objects defined by surfaces. A rendering application selects an object in a first image and determines a surface of the object. An initial set of illumination values is calculated and is separated into low and high spatial frequency components associated with the surface of the object. The rendering application independently adjusts the illumination values of the low and high spatial frequency components based lighting information in the first image, and generates a modified set of illumination values by combining the adjusted low and high spatial frequency components. The surface of the object is then rendered using the modified set of illumination values. Advantageously, embodiments of the invention provide techniques for rendering an object without introducing halo effects around the object. Additionally, embodiments of the invention provide for rendering a sequence of frames without introducing fluctuations in the low frequency components from across frame.

Tone mapping for motion pictures

A contribution of a geometric element's attribute to a value of the image sample is determined analytically for an analytic dimension of evaluation and using sampling for a discrete dimension of evaluation. Motion blur effects are rendered by analytically determining the proportions of shutter time during which image samples are exposed to objects. Space-time projections are determined by the geometry edges' positions at the beginning and the end of the shutter time, which define surfaces of space-time projections. The times that the sample ray of an image sample enter and leave the space-time projections specify the proportions of the image sample's shutter time during which scene geometry is exposed to image sample points. The attribute value of an image sample point is determined from values of all of the scene geometry visible to the image sample point during the shutter time, each weighted by the time that it is visible.

Hybrid analytic and sample-based rendering of motion blur in computer graphics

Surfaces without a global surface coordinate system are divided into surface regions having local surface coordinate systems to enable the caching of surface attribute values. Surface attribute functions are evaluated to determine surface attribute values for the surface regions. A surface attribute value for a surface region may include contributions from two or more adjacent surfaces. A multiresolution cache stores surface attribute values at different resolution levels for surface regions of one or more surfaces, which may be discontiguous. Surface attribute values for a surface are retrieved from the multiresolution cache by dividing the surface into surface regions at a desired resolution level and selecting a corresponding resolution level of the multiresolution cache. One or more cached surface attribute values are retrieved for each surface region. Surface attribute values can be artistically or procedurally generated and can specify surface attributes including optical, illumination, animation, simulation, modeling, or rendering attributes.

A method for a computer system includes opening a model of an object, wherein the model comprises a plurality of geometric elements, determining a subset of geometric elements from the plurality of geometric elements of the model, modifying properties of one or more of the geometric elements in the subset of geometric elements to form a modified subset of geometric elements, and using the modified subset of geometric elements to represent the model of the object in the computer system.

Dynamic model generation methods and apparatus

Function spaces defined by scaling functions are used to generate bandlimited noise octaves and other attribute data sets. Scaling functions are basis functions that admit multiresolution analysis and include piecewise constant scaling functions, piecewise polynomial scaling functions, bandlimited scaling functions, Daubeschies scaling functions, as well as other multiresolution analysis scaling basis functions known to those of skill in the art. Scaling basis functions can be locally supported or have infinite support. The properties of the scaling basis functions used to construct bandlimited noise octaves may ensure that any bandlimited noise octave at resolution level N is orthogonal to bandlimited noise octaves and their associated scaling basis functions at all resolution levels less than N. Bandlimited noise octaves can be scaled to any resolution level and guaranteed to have no effect on images at any lower resolution level.

Method of bandlimiting data for computer graphics

A method for a computer system includes determining first shading results associated with a geometric object in response to first shading computations and first shading data associated with the geometric object and associated with both a first scene and a second scene, determining second shading results associated with the geometric object in response to second shading computations and second shading data associated with the geometric object, and determining first combined shading results associated with the geometric object in response to the first shading results and to the second shading results, wherein the first combined shading results is associated with the second scene, wherein a second combined shading results is associated with the geometric object, wherein the second combined shading results is associated with the first scene, and wherein the second combined shading results is not determined in response to the second shading results.

Shot shading method and apparatus

A method for a computer system includes receiving a geometric description of an object to be rendered in a first image and a second image, and performing a plurality of rendering operations for the object for the first image and for the second image, wherein the plurality of rendering operations includes a first plurality of rendering operations and at least a second rendering operation, wherein the second rendering operation for the object for the first image and the second rendering operation for the object for the second image are substantially similar, wherein the first plurality of rendering operations is performed for the first image, wherein the first plurality of rendering operations is performed for the second image, and wherein the second rendering operation is performed once for both the first image and for the second image.

Shot rendering method and apparatus

A method for shading objects in a first image and a second image includes receiving a geometric description of a first object, performing once for both the first image and the second image, a first set of shading operations for the first object, performing a second set of shading operations for the first object in the first image, performing a third set of shading operations for the first object in the second image, combining results of the first set of shading operations for the first object and results of the second set of shading operations for the first object to determine shading values of the first object in the first image, and combining results of the first set of shading operations for the first object and results of the third set of shading operations for the first object to determine shading values of the first object in the second image.

Growing community of inventors

San Anselmo, CA, United States of America

Robert L Cook