Abstract: To prevent correlated data from being inadvertently altered by subsequent modifications or additions, changes to correlated data are automatically detected. Corrections may be automatically applied to data to preserve data correlation. Change detection data is determined from an initial correlation between source data and dependent data. The change detection data is stored in association with the dependent data. A subsequent evaluation of the data defines a current correlation between the source data and the dependent data. The current correlation is evaluated with the change detection data to determine if the current correlation differs from the initial correlation. If the current correlation between source data and dependent data does not match the initial correlation, the current correlation is reevaluated using topological; geometric, or other analysis techniques. The reevaluated correlation can be provided as part of the authored state of a computer graphics component.

Abstract: Unordered list operations are used to create and modify ordered lists of components. Each list operation specifies an intention to change some aspect of an ordered list, such as the addition or removal of components or a change in the sequence of components. List operations are associated with intrinsic and extrinsic time-independent attributes. Multiple users can collaborate on an ordered list by specifying their own list operations. List operations are cumulative and do not destructively overwrite list operations from previous pipeline activities. An embodiment of the invention interprets list operations in a time independent manner using intrinsic and extrinsic list operation attributes. Because list operations are processed in a time-independent manner, multiple users may collaborate in any order on the creation of an ordered list, including simultaneously editing the ordered list, and still obtain consistent results.

Abstract: Computer-generated images are generated by evaluating point positions of points on animated objects in animation data. The point positions of the points are used by an animation system to determine how to blend animated sequences or frames of animated sequences in order to create realistic moving animated characters and animated objects. The methods of blending are based on determining distances or deviations between corresponding points and using blending functions with varying blending windows and blending functions that can vary from point to point on the animated objects.

Abstract: A method of animation of surface deformation and wrinkling, such as on clothing, uses low-dimensional linear subspaces with temporally adapted bases to reduce computation. Full space simulation training data is used to construct a pool of low-dimensional bases across a pose space. For simulation, sets of basis vectors are selected based on the current pose of the character and the state of its clothing, using an adaptive scheme. Modifying the surface configuration comprises solving reduced system matrices with respect to the subspace of the adapted basis.

Abstract: Systems and methods can provide computer animation of animated scenes or interactive graphics sessions. A grid camera separate from the render camera can be created for segments where the configurations (actual or predicted) of the render camera satisfy certain properties, e.g., an amount of change is within a threshold. If a segment is eligible for the use of the separate grid camera, configurations of the grid camera during a segment can be determined, e.g., from the configurations of the render camera. The configurations of the grid camera can then be used to determine grids for rendering objects. If a segment is not eligible for the use of the grid camera, then the configurations of the render camera can be used to determine the grids for rendering.

Abstract: Optimally-sized bounding boxes for scene data including procedurally generated geometry are determined by first determining whether an estimated bounding box including the procedural geometry is potentially visible in an image to be rendered. If so, the procedural geometry is generated and an optimal bounding box closely bounding the procedural geometry is determined. The generated procedural geometry may then be discarded or stored for later use. Rendering determines if the optimal bounding box is potentially visible. If so, then the associated procedural geometry is regenerated and rendered. Alternatively, after the estimated bounding box is potentially visible, the generated procedural geometry may be partitioned into subsets using a spatial partitioning scheme. A separate optimal bounding box is determined for each of the subsets. During rendering, if any of the optimal bounding boxes are potentially visible, the associated procedural geometry is regenerated and rendered.

Abstract: Systems and methods for customizing animation variables and modifications to animation variables in an animation system are provided. An animated model may be comprised of a hierarchical structure of rigs and sub-rigs. An animator may customize the location of animation variables within the hierarchical structure through a relocation operation from an original position to a relocated position. The animation system identifies the relocation operation, resulting in an association being generated between the original position and the relocated position. Modifications made to animation variables in the animation system may be received by the animation system and the animator can customize the scope of the modification and its application to the animated model or animated scene.

Abstract: Techniques are disclosed for stably simulating stylized curly hair that address artistic needs and performance demands, both found in the production of feature films. To satisfy the artistic requirement of maintaining a curl's helical shape during motion, a hair model is developed based upon an extensible elastic rod. A method is provided for stably computing a frame along a hair curve for stable simulation of curly hair. The hair model introduces a new type of spring for controlling the bending and twisting of a curl and another for maintaining the helical shape during extension. The disclosed techniques address performance concerns often associated with handling hair-hair contact interactions by efficiently parallelizing the simulation. A novel algorithm is presented for pruning both hair-hair contact pairs and hair particles.

Abstract: In various embodiments, one or more control structures having sufficient detail or resolution to generate complex deformations of a computer generated model can be bound to the model. These control structures can be bound to the model in a fixed reference pose and used as intermediate control structures for controlling a variety of deformations. In one aspect, to facilitate articulation of all or a portion of the model, a set of one or more intermediate control structures may be reparameterized using one or more additional control structures. An additional control structure can be bound to an intermediate control structure dynamically at pose time. An additional control structure bound to an intermediate control structure may include only enough detail or resolution required for specific subsets of the deformations that may be produced by the intermediate controls structure.

Abstract: An efficient numerical method for accurately rendering translucent materials using photon beam diffusion is provided that can account for multilayer materials and directional incident and exitant effects at the surface. In an embodiment, refracted incident light is represented continuously as a photon beam instead of as discrete photons. An integration scheme for calculating a radiant exitance value at a point on the surface of the translucent material is disclosed that uses importance sampling and evaluates a radiant function at a limited number of points along the beam.

Abstract: Techniques are proposed for animating a plurality of objects in a computer graphics environment. A crowd choreography system receives a first beat description defining potential motions for the plurality of objects, where the first beat description includes a first motion characteristic. The crowd choreography system selects a first object from the plurality of objects and selects a first value for the first motion characteristic based on the first beat description. The crowd choreography system creates a first motion path for the first object based on the first value and animates the first object based on the first motion path.

Abstract: A system and method of animating an object using chained kinematic logic is provided. An animated object may be comprised of several components, each having a corresponding solver. An animator may designate a final desired position of a primary component. The method further includes automatically determining a hierarchical chained relationship between the primary component and one or more secondary associated components. Using chained kinematic logic defined by constraints, the statuses of the solvers for the secondary components may change based on the statuses of the primary component's solver and final desired position. Thus, a pose of the entire object, including the states of all its associated secondary components, may change based on an updated status of the solver of the first component designated by the animator.

Abstract: In various embodiments, a cloth weave structure is built from curves over the surface of a subdivision mesh at rendertime. A coherent woven or knitted surface is generated from interwoven curve geometry and a subdivision (or polygon) mesh. In one aspect, this is done at render-time. Accordingly, in one embodiment, a geometry generation process takes an ST map as input to control the direction of flow of curves (yarns) over the surface. Since each face is calculated independently, general global coordinates in ST space are predefined (at the beginning of the render) to make sure that each face transitions smoothly to the next.

Abstract: A simulation application simulates a fluid flow. The simulation application divides a fluid into coarse volumetric elements (voxels) at a first resolution, and simulates the fluid flow at the first resolution. The simulation application defines a three-dimensional window that includes a portion of the coarse voxels. The simulation application divides each coarse voxel in the portion of the coarse voxels that lie within the three-dimensional window into a plurality of fine voxels at a second resolution. The simulation application simulates the fluid flow associated with each fine voxel in the plurality of fine voxels at the second resolution based at least in part on the simulation at the coarse resolution.

Abstract: State handles mark application data states within a sequence of operations for preservation. Applications can maintain non-linear sets of operations that include multiple sequences of operations between state handles. Applications can determine a sequence of operations between any two state handles, allowing applications to change from the data state associated with one state handle to the data state associated with another state handle. The sequence of operations between any two state handles may include executing operations and/or reversing operations. An application automatically adds new branches in the set of operations to preserve the sequences of operations necessary to reconstruct data states of previously set handles and removes branches that are not needed.

Abstract: Systems and methods for deformation of surface objects are disclosed. A method may include receiving an initial pose of a model comprising an underlying object and a plurality of surface objects, and a deformation of the model to a second pose. A measurement of the surface objects in the second pose can be used to determine inversely distorted surface objects, such that the lengths of the edges in the inversely distorted surface object are adjusted to counteract the distortion. Thus, when the inversely distorted surface objects are deformed to the second pose, they may appear less distorted than when the original surface objects are deformed to the second pose. Furthermore, a user may direct the level of inverse distortion, so that the surface objects, when inversely distorted and deformed to the second pose, may appear entirely rigid, entirely flexible, or some combination thereof.

Abstract: In an animation authoring system wherein knots along curves are provided in only selected frames, a method of breaking down knots in adjacent poses is automated without causing discontinuities in curves between poses by setting a first pose as a guarded frame for an object so that at least some of the values for animation variables (avars) in the guarded frame are protected and an animation variable (avar) having no knot at the guarded frame is merely implicit, then introducing a new knot for that avar position at a non-guarded frame, and introducing an implicit knot by setting its avar for the guarded frame at its previous implicit value. The new position can be effected by either adding a knot or removing a knot at a non-guarded frame. The invention provides a predictable workflow that cannot be changed retroactively when adjacent animation variables on a curve are changed.

Abstract: Systems and methods can be used to store data in a temporal voxel buffer. A first voxel array is stored in association with a first voxel in a voxel grid. The first voxel array includes a plurality of time values. A parameter value is stored in association with each time value of the first voxel array. A second voxel array is stored in association with a second voxel in the voxel grid. The second voxel array stores at least one time value. At least one parameter value is stored in association with the at least one time value of the second voxel array. At least one of the time values stored in the first voxel array is different from each of the at least one time value included in the second voxel array.

Abstract: A method of animation of surface deformation and wrinkling, such as on clothing, uses low-dimensional linear subspaces with temporally adapted bases to reduce computation. Full space simulation training data is used to construct a pool of low-dimensional bases across a pose space. For simulation, sets of basis vectors are selected based on the current pose of the character and the state of its clothing, using an adaptive scheme. Modifying the surface configuration comprises solving reduced system matrices with respect to the subspace of the adapted basis.

Abstract: Systems and methods can be used to generate data to be stored in a temporal voxel buffer. A renderer can receive at least one input primitive and a voxel grid. A sampling lattice can be generated based on the at least one input primitive and the sampling lattice can be shaded. Each voxel of the voxel grid can be sampled at a plurality of sample times and a plurality of sample positions within the voxel. A voxel buffer is generated for the voxel grid. The voxel buffer stores a voxel array in association with each voxel of the voxel grid based on the sampling.