High Quality Content by WIKIPEDIA articles! An octree is a tree data structure in which each internal node has exactly eight children. Octrees are most often used to partition a three dimensional space by recursively subdividing it into eight octants. Octrees are the three-dimensional analog of quadtrees. The name is formed from oct + tree, and normally written "octree", not "octtree". Octrees are often used in 3D graphics and 3D game engines.