Applications
Min/max kd-trees are used for ray casting isosurfaces/MIP (maximum intensity projection). Isosurface ray casting only traverses nodes for which the chosen isovalue lies between the min/max values of the current node. Nodes that do not fulfill this requirement do not contain an isosurface to the given isovalue and are therefore skipped (empty space skipping). For MIP, nodes are not traversed if their maximum is smaller than the current maximum intensity along the ray. The favorible visualization complexity of ray casting allows to ray cast (and even change the isosurface for) very large scalar fields at interactive framerates on commodity PCs. Especially implicit max kd-trees are an optimal choice for visualizing scalar fields defined on rectilinear grids (see ). Similarly an implicit min/max kd-tree may be used to efficiently evaluate queries such as terrain line of sight.
Read more about this topic: Min/max Kd-tree