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Description
Intro
Hi!
I am a undergrad student at SJTU, I use MuJoCo for my research on robot manipulation.
My setup
mujoco 3.3.0, mujoco-mjx 3.2.7, Python, Ubuntu 20.04
What's happening? What did you expect?
I used the following command to load my model in MJX and visualize:
JAX_PLATFORM_NAME=cpu python -m mujoco.mjx.viewer --mjcf scene.xml
I noticed that a significant penetration occurs between the mesh of a bottle and a box.
2025-03-07.17.26.45.webm
However, when I removed three empty bodies from the model, this penetration issue seemed to disappear.
I am unsure why this behavior occurs, as my previous understanding was that empty bodies should not affect the physics simulation.
Steps for reproduction
- Run
JAX_PLATFORM_NAME=cpu python -m mujoco.mjx.viewer --mjcf scene.xml
- Observe penetration between bottle mesh and the box
- Comment out L72-74 in r0_real2sim.xml (as shown in r0_real2sim_1.xml).
<!-- <body name='a' pos="1.05 0.25 0.97"/>
<body name='b' pos="1.05 0.283 0.97"/>
<body name='c' pos="1.05 0.217 0.97"/> -->- Run the viewer again; observe that the mesh penetration issue disappears.
Minimal model for reproduction
Code required for reproduction
No response
Confirmations
- I searched the latest documentation thoroughly before posting.
- I searched previous Issues and Discussions, I am certain this has not been raised before.