SMOOTH TRANSITIONS IN TEXTURE-BASED SIMPLIFICATION

We are investigating techniques for providing smooth transitions when simplifying large, static geometric models with texture-based represen tations (or impostors). Traditionally, textures have been used to repl ace complex geometry, for example the books on a shelf or the complex foliage on a tree. Using textures in a more general manner is a relati vely new area of research. The key idea is that 2D image textures can be used to temporarily represent 3D geometry. Rendering speed is incre ased if a replacement texture can be used for several frames, since te xtures can be rendered quickly and independently of model complexity. Because a texture is only correct from a single viewpoint, visual disc ontinuities, such as misalignment with adjacent geometry, begin to app ear as the texture is used from other viewpoints. Previous approaches have controlled these errors by re-rendering the textures often or pro viding a large set of precomputed textures. We have improved upon thes e methods by developing algorithms for: (a) providing continuous image ry across borders between geometry and sampled textures at all times; (b) providing smooth dynamic transitions between geometry and texture. (C) 1998 Elsevier Science Ltd. All rights reserved.