Hex-meshing is the process of breaking a computer model of a physical object into hexahedron (brick) elements suitable for computer simulation.

Hexahedron elements are preferred over tetrahedron elements because the added complexity of their shape lends itself to better approximation of physical shape and mathematical function. Fewer well-formed hexahedron elements are required than tetrahedron elements for the same simulation accuracy, especially for fluid codes which analyze boundary behavior; for this reason simulation code time can be greatly reduced by using a good hex mesh instead of a tet mesh.

Hexahedron elements are preferred for most computer simulations, but only if the elements are nearly cubic. Most simulation codes are forced to use tetrahedron elements because hexahedron element meshes are difficult to generated.