Roboticists Debate Contact Tuning as MuJoCo Defaults Prove Too Soft

Roboticists debated simulator contact reliability: Kevin Zakka proposed stress-testing by dropping 30,000 cubes onto a height field, noting MuJoCo's soft defaults require tuning solref/solimp while Newton performed solidly. One developer reproduced 1cm penetration in Isaac Sim with a 100kg mass on a 0.5kg plate and fixed it through parameter tuning.

2026-09-14 ~ 2026-09-15 · 4 related posts

• MuJoCo penetration stress test: 30k cubes on a heightfield, tune solref/solimp for stiffer contacts — kevin_zakka · 2026-09-14
• Robot sim stress test: drop 30k cubes to check penetration, MuJoCo defaults are soft — ChongZzZhang · 2026-09-14
• Dropping 100kg on a 0.5kg plate: sim contact penetration fixed by tuning solref/solimp — ChongZzZhang · 2026-09-15
• 100kg Unitree foot on a 0.5kg ramp in sim: setting restitution to 0 works — ChongZzZhang · 2026-09-15