Analytic Eigensystems for Isotropic Distortion Energies Supplemental Material

1 2D DEFORMATIONS VIA COMPLEX NUMBERS The derivatives of distortion energies inR2 were recently considered by Chen and Weber [2017]. In contrast to our work, this method analyzed energies using Wirtinger derivatives obtained by expressing 2D deformations with complex numbers. We now review this complex-based formulation and compare its results to ours. Importantly, we show that Wirtinger derivatives are restricted to 2D and, therefore, the results in Chen and Weber [2017] do not extend to 3D. In contrast, ours is suited to both 2D and 3D.