Systems and methods for elliptical filtering

Abstract

An improved attribute determination process allows the sharpness of a surface attribute function to be adjusted on a per-object, per-surface, per-texture, per-function, or other appropriate basis. A computer-based animator then can selectively adjust the sharpness or other attribute(s) of portions of a to-be-rendered image without significantly increasing the rendering time. For a selected texture, corresponding sampling regions will be shifted about the respective surface points projected in texture space. A multi-dimensional set of sub-regions can be generated for the shifted sampling region. Bounding boxes can be determined for each sub-region, the boxes occupying less area, such as in texture space, than a single bounding box for the original sampling region. The bounding boxes can be used for local attribute determinations (such as texture lookups) for each sub-region, with the local attributes being processed to determine an attribute for the respective surface point.