Smooth transitions in texture-based simplification

We are investigating techniques for providing smooth transitions when simplifying large, static geometric models with texture-based representations (or impostors). Traditionally, textures have been used to replace 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 relatively new area of research. The key idea is that 2D image textures can be used to temporarily represent 3D geometry. Rendering speed is increased if a replacement texture can be used for several frames, since textures can be rendered quickly and independently of model complexity. Because a texture is only correct from a single viewpoint, visual discontinuities, such as misalignment with adjacent geometry, begin to appear as the texture is used from other viewpoints. Previous approaches have controlled these errors by re-rendering the textures often or providing a large set of precomputed textures. We have improved upon these methods by developing algorithms for: (a) providing continuous imagery 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.