Hierarchical View-Dependent Structures for Interactive Scene Manipulation

The result of a scene manipulation is usually displayed by rerendering the entire image even if the change has affected only a small portion of it. This paper presents a system that efficiently detects and recomputes the exact portion of the image that has changed after an arbitrary manipulation of a scene viewed from a fixed camera. The incremental rendering allows for all visual effects produced by ray tracing, including shadows, reflections, refractions, textures, and bump maps. Two structures are maintained to achieve this. A ray tree is associated with each pixel and is used to detect and rebuild only the modified rays after an optical or geometrical change. A color tree represents the complete color expression of a pixel. All changes affecting the color of a pixel without changing the corresponding ray tree require only re-evaluation of the affected portions of the color tree. Optimizations are presented to efficiently detect the modified structures by the use of strategies such...

• Type: Conference
• Year: 1996
• Where: SIGGRAPH
• Authors: Normand Brière, Pierre Poulin
• Keywords: Color Tree, Computer Graphics, Incremental Rendering, Ray Tree, SIGGRAPH 1996