Editing Octree (section)

==For spatial representation==
Each node in an octree subdivides the space it represents into eight [[octant (solid geometry)|octant]]s. In a point region (PR) octree (analogous to a point quadtree), the node stores an explicit [[Point (geometry)|three-dimensional point]], which is the "center" of the subdivision for that node; the point defines one of the corners for each of the eight children. In a matrix-based (MX) octree (analogous to a region quadtree), the subdivision point is implicitly the center of the space the node represents. The root node of a PR octree can represent infinite space; the root node of an MX octree must represent a finite bounded space so that the implicit centers are well-defined. Note that octrees are not the same as [[k-d tree|''k''-d trees]]: ''k''-d trees split along a dimension and octrees split around a point. Also ''k''-d trees are always binary, which is not the case for octrees.
By using a [[depth-first search]] the nodes are to be traversed and only required surfaces are to be viewed.