Hierarchical extraction of iso-surfaces with semi-regular meshes

Abstract

In this paper we present a novel approach to iso-surface extraction which is based on a multiresolution volume data representation and hierarchically approximates the iso-surface with a semi-regular mesh. After having generated a hierarchy of volumes, we extract the iso-surface from the coarsest resolution with a standard Marching Cubes algorithm, apply a simple mesh decimation strategy to improve the shape of the triangles, and use the result as a base mesh. Then we iteratively fit the mesh to the iso-surface at the finer volume levels, thereby subdividing it adaptively in order to be able to correctly reconstruct local features. We also take care of generating an even vertex distribution over the iso-surface so that the final result consists of triangles with good aspect ratio. The advantage of this approach as opposed to the standard method of extracting the iso-surface from the finest resolution with Marching Cubes is that it generates a mesh with subdivision connectivity which can be utilized by several multiresolution algorithms. As an application of our method we show how to reconstruct the surface of archaeological items.