Techniques and workflows for computer graphics animation system

摘要

The disclosed implementations describe techniques and workflows for a computer graphics (CG) animation system. In some implementations, systems and methods are disclosed for representing scene composition and performing underlying computations within a unified generalized expression graph with cycles. Disclosed are natural mechanisms for level-of-detail control, adaptive caching, minimal re-compute, lazy evaluation, predictive computation and progressive refinement. The disclosed implementations provide real-time guarantees for minimum graphics frame rates and support automatic tradeoffs between rendering quality, accuracy and speed. The disclosed implementations also support new workflow paradigms, including layered animation and motion-path manipulation of articulated bodies.

主权项

1. A computer graphics animation method, wherein user inputs are received by a computer graphics program and motion sequences of elements of a geometric model in a scene space are output corresponding, at least approximately, to the user inputs, the method comprising:
accessing an expression graph corresponding to the geometric model, wherein the expression graph includes at least one directed, acyclic, rooted scene tree; receiving user input corresponding to at least one reference point, wherein the at least one reference point is associated with an element of the geometric model; receiving user input corresponding to a desired motion path for the at least one reference point; determining avars in the expression graph that relate to motion of the at least one reference point, thereby determining which avars would alter position of the at least one reference point; computing the desired motion path based at least in part on changes in the position of the at least one reference point; and determining values for the determined avars such that evaluation of the expression graph with the determined values results in the at least one reference point following, at least approximately, the desired motion path.