Dependency-Free Parallel Progressive Meshes

The constantly increasing complexity of polygonal models in interactive applications poses two major problems. First, the number of primitives that can be rendered at real-time frame rates is currently limited to a few million. Second, less than 45 million triangles – with vertices and normal – can be stored per gigabyte. While the rendering time can be reduced using level-of-detail (LOD) algorithms, representing a model at different complexity levels, these often even increase memory consumption. Out-of-core algorithms solve this problem by transferring the data currently required for rendering from external devices. Compression techniques are commonly used because of the limited bandwidth. The main problem of compression and decompression algorithms is the only coarse grained random access. A similar problem occurs in view-dependent LOD techniques. Due to the inter-dependency of split operations, the adaption rate is reduced leading to visible popping artifacts during fast movements. In this paper, we propose a novel algorithm for real-time view-dependent rendering of gigabyte-sized models. It is based on a neighborhood dependency free progressive mesh data structure. Using a per operation compression method, it is suitable for parallel random-access decompression and out-of-core memory management without storing decompressed data.