Linear octrees

An octree is said to be complete if every internal node has exactly 8 child nodes. If the maximum permissible depth of an octree is fixed a priori, then it is sufficient to store the complete list of leaf nodes of the octree. Such a representation is referred to a Linear octree, since a linear array is sufficient for this representation instead of the tree data structure. All the nodes of the octree can be generated from the list of its leaf nodes. Space filling curves are often used to represent linear octrees.