Quadtree / octree- to-boundary conversion

Numerous and widely differentiated are the coding schemes proposed for the representation and manipulation of two-dimensional and three-dimensional spatial information: from analytical to vectorial, from raster to cellular or hierarchical, from parametric to algebraic. Each of these representation schemes presents peculiar characteristics with reference to the storage costs, the efficiency of the algorithms, the simplicity of the data manipulation, and so on. For these reasons, it is common to use multiple data representation schemes to fulfil the required space-time efficiency. The quest for efficient scheme conversion algorithms always has been a central theme in the problem of the representation of spatial data.