Quadtree/Octree Data Structures
Adaptive refinement of an initial element (element 0) into three levels (left)
and the corresponding quadtree data structure (right).
The octree (quadtree in 2D) is the basic data structure in Sandia's
adaptive mesh refinement applications. In the octree data structure,
coarse-mesh elements are divided into some number of finer elements. These
fine elements are stored as "children" of the coarse-mesh "parent" element in
a hierarchical data structures.