Supplement for “ Stable Neo - Hookean Flesh Simulation ”

The behavior of the three Neo-Hookean energies is very similar, although the slightly superior volume preservation of our model starts to be seen in the ν = 0.3 row. The “fixed” co-rotational model preserves volume, but unnatural crinkling artifacts start to appear even at small Poisson’s ratios, e.g. ν = 0.2. The original co-rotational model yields good results at ν = 0.2, but quickly begins to lose volume at ν = 0.3, and starts to severely invert at ν = 0.4. The StVK model with cubic compression resistance does not collapse like the co-rotational model, but instead gains significant volume (83%) under extension. This is expected, as the volumetric term deactivates under extension. The compression resistance term was set to κ = 8× 108. This setting was selected by running a sweep of elbow flexion simulations over the range κ ∈ [0, 1.4 × 109] for ν = 0.49 and retaining the setting that exhibited the best volume preservation. Thus, these results are likely to be close to the highest quality that the model is able to produce.