David E. Baraff - Oakland CA Andrew Witkin - Oakland CA
Assignee:
Pixar Animation Studios - Emeryville CA
International Classification:
G06T 1300
US Classification:
345474, 345958, 345473
Abstract:
A method and an apparatus allows animators to control the extent by which scripted character motions affect simulated objects motions. The simulated objects are connected to the character or non-simulated object, such as clothing or hair, and the motion of the simulated objects is simulated based on the motion of the character or non-simulated object. Collision flypapering is employed to yield the proper behavior of simulated objects when those objects are pinched by surfaces of the character and/or other collision objects.
Global Intersection Analysis For Determining Intesections Of Objects In Computer Animation
David E. Baraff - Oakland CA, US Andrew Witkin - Oakland CA, US Michael Kass - Berkeley CA, US
Assignee:
Pixar - Emeryville CA
International Classification:
G06T013/00 G06T017/00
US Classification:
345473, 345420
Abstract:
A method of globally analyzing intersections between objects in computer animation includes providing objects represented by meshes, with each of the meshes being formed by a set of vertices, where a set of pairs of vertices defines a set of edges of the mesh. All edges of the meshes are checked to determine if the edges intersect with any of the meshes. An intersection path, formed by the intersection of the meshes, is traced and which vertices that are contained within the intersection path are determined. A polarity of each of the contained vertices is set to indicate that those vertices are contained within the intersection path. The analysis forms the backbone of a collision-response algorithm for unoriented objects such as cloth that is better than previous existing algorithms. The analysis also allows objects to be simulated even when hand-animated elements of the simulation have extreme amounts of interpenetration. Finally, simply displaying the nature and extent of the data found from the analysis provides extremely useful feedback to an end-user.
Inertial Field Generator: A Method For Controllably Coupling Kinematic Character Motions To Dynamically Simulated Elements
David E. Baraff - Emeryville CA, US Andrew Witkin - Emeryville CA, US
Assignee:
Pixar - Emeryville CA
International Classification:
G06G 7/56 G06T 13/00 G06T 17/00 G06G 17/50
US Classification:
703 7, 345420, 345474
Abstract:
A method is described to let animators control the extent by which kinematically scripted character motions affect dynamically simulated objects' motions. The dynamic objects are connected to the kinematic character, such as clothing or hair, and the motion of the dynamic objects is simulated based on the motion of the kinematic character. Such control is important to produce reasonable behavior of dynamic objects in the presence of physically unrealistic kinematic character motion. An Inertial Field Generator (IFG) is employed to compensate for the unreasonable behavior of dynamic objects when the kinematic character undergoes unrealistic motion.
Global Intersection Analysis For Determining Intersections Of Objects In Computer Animation
David E. Baraff - Oakland CA, US Andrew Witkin - Oakland CA, US Michael Kass - Berkeley CA, US
Assignee:
Pixar - Emeryville CA
International Classification:
G06T 13/00
US Classification:
345473, 345441, 345420, 345629, 345597
Abstract:
A method of globally analyzing intersections between objects in computer animation includes providing objects represented by meshes, with each of the meshes being formed by a set of vertices, where a set of pairs of vertices defines a set of edges of the mesh. All edges of the meshes are checked to determine if the edges intersect with any of the meshes. An intersection path, formed by the intersection of the meshes, is traced and which vertices that are contained within the intersection path are determined. A polarity of each of the contained vertices is set to indicate that those vertices are contained within the intersection path. The analysis forms the backbone of a collision-response algorithm for unoriented objects such as cloth that is better than previous existing algorithms. The analysis also allows objects to be simulated even when hand-animated elements of the simulation have extreme amounts of interpenetration. Finally, simply displaying the nature and extent of the data found from the analysis provides extremely useful feedback to an end-user.
Robert Jensen - Berkeley CA, US Andrew Witkin - Oakland CA, US
Assignee:
Pixar - Emeryville CA
International Classification:
G06F 7/00 G06F 17/00
US Classification:
7071041, 707200, 703 6, 345473, 345419
Abstract:
A method for a computer system includes opening a first file describing a first object in an object environment, determining a reference for a second object, wherein the second object includes a plurality of attributes, receiving a second file describing the second object from a storage system; in response to the reference, and opening the second file describing the second object in the object environment, determining a modified value for an attribute from the plurality of attributes for the second object, and including in the first file the reference for the second object and the modified value for the attribute, wherein the second object is not stored in the first file.
Techniques For Automatically Maintaining Continuity Across Discrete Animation Changes
Frank Sebastian Grassia - Mountain View CA, US Thomas Hahn - Piedmont CA, US Malcolm Blanchard - Glen Ellen CA, US Marco Jorge da Silva - Oakland CA, US Andrew Witkin - Oakland CA, US
Assignee:
Pixar - Emeryville CA
International Classification:
G06T 13/00
US Classification:
345473
Abstract:
Techniques for automatically maintaining continuity in animation across discrete animation changes. Smooth animation is achieved without forcing the animator to manually calculate compensation values or introducing extra controls to the models that are animated. Continuity or smoothness of the animation is maintained as varying aspects of the animation change under continued authoring.
Inertial Field Generator: A Method For Controllably Coupling Kinematic Character Motions To Dynamically Simulated Elements
David E. Baraff - Emeryville CA, US Andrew Witkin - Emeryville CA, US
Assignee:
Pixar - Emeryville CA
International Classification:
G06T 13/00 G06F 7/60 G06G 7/48
US Classification:
345473, 345474, 345475, 703 7, 703 2
Abstract:
A method is described to let animators control the extent by which kinematically scripted character motions affect dynamically simulated objects' motions. The dynamic objects are connected to the kinematic character, such as clothing or hair, and the motion of the dynamic objects is simulated based on the motion of the kinematic character. Such control is important to produce reasonable behavior of dynamic objects in the presence of physically unrealistic kinematic character motion. An Inertial Field Generator (IFG) is employed to compensate for the unreasonable behavior of dynamic objects when the kinematic character undergoes unrealistic motion.
Interpolation Between Model Poses Using Inverse Kinematics
The pose of the model at an evaluation time is determined by interpolating pose attributes of the unconstrained pose degrees of freedom from previously defined poses. A neutral value of an attractor function at the evaluation time is based at least on the pose attributes of the unconstrained pose degrees of freedom. Because of this, the attractor function is time coherent. Similarly, pose constraints are determined by interpolating from previously defined pose constraints. Inverse kinematics or error minimization techniques modify the pose attributes of the unconstrained pose degrees of freedom to minimize the difference between the attractor function value for the pose attributes and the neutral value of the attractor function. The final pose of the model at the evaluation time is specified by the pose attributes corresponding with this minimization.