Rendering complexity in computer-generated pen-and-ink illustrations

We present a method to aid in the generation of pen-and-ink style renderings of complex geometry. Most illustration algorithms focus on rendering a small number of surfaces with as much detail and expression as possible. These methods break down when the scene is composed of many small, overlapping details that are not individually resolvable. We propose a hybrid 2D/3D pipeline that incorporates image processing with the full scene geometry to extract regions which may require special handling. For silhouette renderings, grayscale value is matched to a sample rendering while preserving important edges and texture. For hatched areas, the approximate surface properties of each logical region is represented. The result is an image that is more clear for informative purposes, and more artistic for aesthetic purposes.