A Rhombic dodecahedron has two types of vertices. Therefore there exist three different kinds of truncation, whether only one or both of the vertex types are truncated. In his book Structure in Nature is a Strategy for Design Peter Pearce showed that all three can be used as space filling systems, in combination with cubes and/or tetrahedra. The depth of truncation of both vertex types is arbitrary. The canonical choice leads to a truncated rhombic dodecahedron which can be inscribed in a sphere. Another choice achieves edges of equal lengths. In this post, the depth of truncation is chosen in such a way that the truncated rhombic dodecahedron and its space filling systems can be constructed with standard Zometool struts (blue, green and yellow).
Even when one truncates only one type of vertices, the resulting space filling systems can be constructed with Zometool, if a specific depth of truncation is chosen. One of these systems requires yellow and half-blue struts, the other one requires yellow and half-green struts.
