1. A method comprising: producing a model of a sample, the sample having a pattern on a layer, the pattern comprising a conductive material and an at least partially transparent material, producing a model of the sample comprises: modeling the pattern based on the effect that the pattern has on incident light that is TE polarized with respect to the pattern, wherein modeling the pattern comprises: generating a first uniform film that combines the optical properties of the conductive material and the at least partially transparent material of the pattern; and generating a second uniform film of the conductive material of the pattern, the second uniform film underlying the first uniform film; wherein producing a model of the sample further comprises storing the model of the sample in a computer-readable storage medium.