Complex media have gained interest in microwave and millimeter-wave devices. They display some interesting characteristics such as, for instance, tunability and controlled filtering capacity. However, such media are generally very complex as they can be fully nonhomogeneous; frequency dependent, anisotropic, time dependent, or chiral. This requires simulation techniques capable of solving Maxwell's equations accounting for such media. Also, apart comparison with rather difficult measurement, canonical solutions are not available for validation. In this paper, the concept of transformation optics (TO) is presented as a systematic tool to construct computational problems involving complex media for which the analytical solution is known. Several examples are shown for validation of a new transmission-line matrix (TLM) cell that model complex media.