Systems and Methods for Building a Pseudo-Muscle Topology of a Live Actor in Computer Animation
AssigneeWeta Digital Limited
InventorByung Kuk Choi
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Abstract
An animation system wherein a machine learning model is adopted to generate animated facial actions based on parameters obtained from a live actor. Specifically, the anatomical structure such as a facial muscle topology and a skull surface that are specific to the live actor may be used. A muscle structure of simplified “pseudo” muscles that approximate the actual muscle topology but with reduced degree of freedom is determined to improve computational efficiency.
Claims20
A computer-implemented method for building a pseudo-muscle topology of a live actor, the method comprising:
- under the control of one or more computer systems configured with executable instructions:
- determining, from a plurality of facial scans of the live actor, a muscle model representing facial muscles of the live actor and a vector of muscle strain values;
- select a subset of facial muscles from the muscle model;
- generating a set of pseudo-muscles that approximate the subset of facial muscles, wherein a respective pseudo-muscle of the set of pseudo-muscles is represented by a respective muscle curve;
- determining a mapping between the selected plurality of muscles and the set of pseudo-muscles;
- determining, for the respective muscle curve representing the respective pseudo-muscle, the start position, the end position and a line-of-action length based on the mapping;
- computing, for the respective pseudo-muscle, a respective pseudo-muscle strain value based on the line-of-action length and a rest length of the respective pseudo-muscle;
- and
- sending the set of pseudo-muscles described by a set of muscle curves and corresponding pseudo-muscle strain values as a substitute of the three-dimensional polygon topology to a machine learning engine for computer animation.
A system for building a pseudo-muscle topology of a live actor, the system comprising:
- a memory;
- and
- a processor reading executable instructions from the memory to:
- determine, from a plurality of facial scans of the live actor, a muscle model representing facial muscles of the live actor and a vector of muscle strain values;
- select a subset of facial muscles from the muscle model;
- generate a set of pseudo-muscles that approximate the subset of facial muscles, wherein a respective pseudo-muscle of the set of pseudo-muscles is represented by a respective muscle curve;
- determine a mapping between the selected plurality of muscles and the set of pseudo-muscles;
- determine, for the respective muscle curve representing the respective pseudo-muscle, the start position, the end position and a line-of-action length based on the mapping;
- compute, for the respective pseudo-muscle, a respective pseudo-muscle strain value based on the line-of-action length and a rest length of the respective pseudo-muscle;
- and
- send the set of pseudo-muscles described by a set of muscle curves and corresponding pseudo-muscle strain values as a substitute of the three-dimensional polygon topology to a machine learning engine for computer animation.
Dependencies are inferred from the claim text.