MPM# gs.materials.MPM.Elastic Elastic Elastic.update_F_S_Jp() Elastic.update_stress_corotation() Elastic.update_stress_neohooken() Elastic.model gs.materials.MPM.ElastoPlastic ElastoPlastic ElastoPlastic.update_F_S_Jp() ElastoPlastic.yield_lower ElastoPlastic.yield_higher ElastoPlastic.use_von_mises ElastoPlastic.von_mises_yield_stress gs.materials.MPM.Liquid Liquid Liquid.update_F_S_Jp() Liquid.update_stress() gs.materials.MPM.Muscle Muscle Muscle.stiffness Muscle.n_groups gs.materials.MPM.Sand Sand Sand.sand_projection() Sand.update_F_S_Jp() Sand.update_stress() gs.materials.MPM.Snow Snow Snow.update_F_S_Jp() Snow.update_stress()