Progressive iso-surface extraction from hierarchical 3D meshes

A multiresolution data decomposition offers a fundamental framework support ing compression, progressive transmission, and level-of-detail (LOD) contro l for large two or three dimensional data sets discretized on complex meshe s. In this paper we extend a previously presented algorithm for 3D mesh red uction for volume data based on multilevel finite element approximations in two ways. First, we present efficient data structures which allow to incre mentally construct approximations of the volume data at lower or higher res olutions at interactive rates. An abstract description of the mesh hierarch y in terms of a coarse base mesh and a set of integer records offers a high compression potential which is essential for an efficient storage and a pr ogressive network transmission. Based on this mesh hierarchy we then develo p a new progressive iso-surface extraction algorithm. For a given iso-value , the corresponding iso-surface can be computed at different levels of reso lution.. Changing to a higher or coarser resolution will update the surface only in those regions where the volume data is being refined or coarsened. Our approach allows to interactively visualize very large scalar fields li ke medical data sets, whereas the conventional algorithms would have requir ed at least an order of magnitude more resources.