Simulating viscoplastic dough in MuJoCo (flex/flexcomp) — elastic solid always springs back, looking for the right approach(reddit.com)

I'm trying to simulate a dough-like deformable object in MuJoCo — start with a ball, roll it flat, and have it stay flat (with some viscoelastic relaxation) instead of springing back to a sphere. Setup: tetrahedral solid flex built with flexcomp, using the native solid elasticity (Young's modulus / Poisson ratio, with damping). Problem: as far as I can tell, MuJoCo's solid elasticity always computes strain relative to a fixed reference configuration baked in at compile time. Adding damping gives you a Kelvin-Voigt viscoelastic response (dissipates energy, slows the recovery down) — but with zero external force it will still fully relax back to the original rest shape eventually. There doesn't seem to be any built-in plastic/Maxwell-type behavior where the reference shape itself updates and the object keeps a permanent deformation. Is that actually correct, or is there an attribute/plugin I'm missing? I am considering writing a custom elasticity plugin that tracks per-tetrahedron plastic strain with a yield criterion (Von Mises + return mapping), similar to what's been discussed for the cable plugin but applied to the solid element. The main idea is bi-manual manipulation for rolling a dough ball into a nearly flatten dough for creating a baseline to compare it with the real hardware. submitted by /u/Boda_Khaled254 [link] [Kommentare]