Deformable-object motion control simulation.
Techniques are proposed for animating a deformable object. A geometric mesh comprising a plurality of vertices is retrieved, where the geometric mesh is related to a first rest state configuration corresponding to the deformable object. A motion goal associated with the deformable object is then retrieved. The motion goal is translated into a function of one or more state variables associated with the deformable object. A second rest state configuration corresponding to the deformable object is computed by adjusting the position of at least one vertex in the plurality of vertices based at least in part on the function.
BACKGROUND OF THE INVENTION(1) Field of the Invention(2) The present invention relates to the field of computer-based animation, in particular, to motion control of active deformable objects.(3) Description of the Related Art(4) Computer generated animation typically involves simulating the locomotion of various objects, such as characters and other virtual actors, in a virtual space. Many objects are articulated, in that such objects include a rigid internal structure that includes the equivalence of bones and joints. Accordingly, this rigid internal structure forms a virtual “skeleton” for the articulated objects. Such objects, such as humanoids and animals, may be animated via physics-based locomotion controllers that translate high-level commands, such as “walk left,” “crouch,” or “jump,” into sequences of joint torques that yield the desired behavior. Deformable objects, on the other hand, are generally passive, in that the objects have no such internal rigid structure to which joint torques may be applied. Examples of deformable objects include jelly-like creatures, walking carpets, singing candelabra, or water-pail-carrying broomsticks.(5) Such a passive deformable object may be animated using physics-based simulation by applying external control forces to the deformable object in order to achieve desired motion objectives. These external forces do not typically sum to zero and may have non-vanishing rotational components. As a result, these external forces may change
1. A method of animating a deformable object, the method comprising: retrieving a geometric mesh comprising a plurality of vertices related to a first rest state configuration corresponding to the deformable object; retrieving a motion goal associated with the deformable object; translating the motion goal into a function of one or more state variables associated with the deformable object; computing a second rest state configuration corresponding to the deformable object by adjusting the position of at least one vertex in the plurality of vertices based at least in part on the function; and rendering one or more image frames depicting the deformable object in at least one of the first and the second rest state configurations, wherein rest state configurations of the deformable object are parameterized such that the rest state configurations of the deformable object are generated based on an initial rest state configuration of the deformable object, displacements of a reduced set of controllable mesh vertices, and a linear map between changes in rest state coordinates and the displacements of the reduced set of controllable mesh vertices.
11. A non-transitory computer-readable storage medium including instructions that, when executed by a processing unit, cause the processing unit to animate a deformable object, by performing steps comprising: retrieving a geometric mesh comprising a plurality of vertices related to a first rest state configuration corresponding to the deformable object; retrieving a motion goal associated with the deformable object; translating the motion goal into a function of one or more state variables associated with the deformable object; computing a second rest state configuration corresponding to the deformable object by adjusting the position of at least one vertex in the plurality of vertices based at least in part on the function; and rendering one or more image frames depicting the deformable object in at least one of the first and the second rest state configurations, wherein rest state configurations of the deformable object are parameterized such that the rest state configurations of the deformable object are generated based on an initial rest state configuration of the deformable object, displacements of a reduced set of controllable mesh vertices, and a linear map between changes in rest state coordinates and the displacements of the reduced set of controllable mesh vertices.
20. A computing system, comprising: a memory that is configured to store instructions for a program; and a processor that is configured to execute the instructions for the program to animate a deformable object, by performing steps comprising: retrieving a geometric mesh comprising a plurality of vertices related to a first rest state configuration corresponding to the deformable object, retrieving a motion goal associated with the deformable object, translating the motion goal into a function of one or more state variables associated with the deformable object, computing a second rest state configuration corresponding to the deformable object by adjusting the position of at least one vertex in the plurality of vertices based at least in part on the function, and rendering one or more image frames depicting the deformable object in at least one of the first and the second rest state configurations, wherein rest state configurations of the deformable object are parameterized such that the rest state configurations of the deformable object are generated based on an initial rest state configuration of the deformable object, displacements of a reduced set of controllable mesh vertices, and a linear map between changes in rest state coordinates and the displacements of the reduced set of controllable mesh vertices.