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 in- teractive rates using a novel data structure, the Normal-Position In- terval tree, and algorithms based on interval arithmetic. After pro- jecting 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 represen- tation of the discontinuities and point samples called the edge-and- point 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 ar- bitrary shaders to collect radiance samples. Our software imple- mentation supports interactive navigation and object manipulation in scenes that include complex lighting effects (such as global illu- mination) and geometrically complex objects. We show that high- quality anti-aliased images of these scenes can be rendered at sev- eral frames per second on typical desktop machines.