Combining Edges and Points for Interactive Anti-Aliased Rendering

This paper presents a new rendering and display paradigm that uses both discontinuities (edges) and sparsely sampled shading (points) to interactively generate anti-aliased images of complex scenes. Geometric and shadow discontinuities in the image are found at interactive rates using a novel data structure, the Normal–Position Interval tree, and algorithms based on interval arithmetic. After projecting discontinuities onto the image plane, shading information is interpolated from nearby point samples while never interpolating across a discontinuity edge. We introduce a new compact representation of the discontinuities and point samples called the edge-andpoint image. An efficient interpolation algorithm uses this image to generate anti-aliased output images at interactive rates without using supersampling. Our rendering technique is extensible, permitting the use of arbitrary shaders to collect radiance samples. Our software implementation supports interactive navigation and object manipulation in scenes that include complex lighting effects (such as global illumination) and geometrically complex objects. We show that highquality anti-aliased images of these scenes can be rendered at several frames per second on typical desktop machines.