Bounding-planes Octree: A New Volume-based Lod Scheme

摘要

In this paper we present a new data structure: the. BP-Octree (Bounding-planes Octree). The BP-Octree is based on a spatial decomposition of the model using an octree, and offers a very tight hierarchy of convex bounding volumes which leads to simplified models. It is done by assigning to each node of the tree a set of planes that, intersected one among others, creates a bounding volume of the part of the model contained in that node. These planes are taken from the real polygons of the model, and are selected at each level guaranteeing that they include completely all boundings of deeper levels. By using this scheme, it is possible to achieve several tasks apart from the inherent collision detection algorithms, such as the progressive transmission of the bounding volume by sending the planes coefficients needed at each level-just the index of each plane if it has been previously transmitted. On the client side, the visualization algorithm is responsible for reconstructing the polygonal geometry from the set of planes just applying a mesh clipping algorithm.