Resolution-independent method for displaying a three dimensional model in two-dimensional display space

摘要

A method for rendering a graphics image of a three-dimensional graphics model is described. The method consists of the steps of projecting a parametric surface representation of the three-dimensional graphics model into a two-dimensional parametric space; mapping an array of grid points onto the parametric space; evaluating a shading function at each grid point to form an array shading values; applying a contouring function to the array of shading values to determine boundary curves for regions of constant shading; applying a silhouette function to the parametric surface representation of the three-dimensional graphics model to determine the boundaries for regions of consistent-facing; clipping the regions of constant shading by the regions of consistent-facing to determine consistent-facing regions of constant color; mapping the regions of constant shading back to the surface of the three-dimensional model; occluding hidden surfaces; mapping the clipped regions of constant shading to display space; and filling the regions of constant shading in display space. The regions of constant shading are available for editing by a two-dimensional drawing package.