Patchwork Terrains

Abstract: We present a radically new method for the management, multi-resolution representation and rendering of large terrain databases. Our method has two main benefits: it provides a Ck representation of terrain, with k depending on the type of base patches; and it supports efficient updates of the database as new data come in. We assume terrain data to come as a collection of regularly sampled overlapping grids, with arbitrary spacing and orientation. A multi-resolution model is built and updated dynamically off-line from such grids, which can be queried on-line to obtain a suitable collection of patches to cover a given domain with a given, possibly view-dependent, level of detail. Patches are combined to obtain a Ck surface. The whole framework can is designed to take advantage of the parallel computing power of modern GPUs. Figure 1: A view-dependent query executed on the Puget Sound Dataset with an on-screen error of one pixel. The different colors represent patches of different sizes.