Combining SP-Octrees and impostors for the visualisation of multiresolution models

Space-Partition Octree (SP-Octree) is a hierarchical representation scheme for solid modelling. It allows a multiresolution representation of polyhedral objects, and has been successfully used in progressive transmission. Moreover, this scheme allows visualising the model in an adaptive way. However, at intermediate levels of the SPOctree, the obtained visualisation is a rough approximation of the object due to the fact that grey nodes are approximated by the face’s planes belonging to the convex hull of the solid included in that node. In this paper, we present an approach that improves the visualisation of these multiresolution SP-Octrees models by applying impostors over those planes that are not part of the solid boundary. This way, it is possible to obtain a more realistic visualisation of the object, although the maximum LOD is not used. At each moment, the impostor is selected depending on the observer’s viewpoint. Each SP-Octree has associated a set of impostors that are views of the modelled complex solid. r 2005 Elsevier Ltd. All rights reserved.