Volumetric Meshing

[DanielPiker]

See this recent discussion

3D mesh for a solid

The term usually used for this is volumetric meshing. If it is with little distorted cube-like elements, then more specifically it is called hexahedral meshing. (the other common type being tetrahedral meshing). Like with quads/triangles, hexahedral meshes are usually harder to generate for general shapes than tetrahedral ones. If it is specifically for this single distorted box-like shape, the method shown by @HS_Kim looks good. If you are looking for something to work with general shapes,…

Also to add another to the ones I mentioned there-
http://www.itascacg.com/software/blockranger