Camera Rendering disrupts MjViewer

[Dhanushvarma]

Intro

Hi!

I am a graduate student , I use MuJoCo for my research on Imitation Learning.

My setup

MuJoCo verison : 3.2.7
MuJoCo API : Python
Python version : 3.12.9
OS : Ubuntu 22.04

My question

I am trying to collect demonstration data using MuJoCo setup. I am trying to operate the robot while using the MjViewer and saving images from cameras in the scene. However when I render the image from the camera, the viewer freezes.

There were similar issue reported, but it was unclear what the solution was.

Pseudo-Code of the problem I am having :

Minimal model and/or code that explain my question

Code:

import mujoco.viewer
from dm_control import mjcf

# Create physics
physics = mjcf.Physics.from_mjcf_model(mjcf.RootElement().mjcf_model)

# Try to use both rendering methods in the same process
def step():
    physics.step()
    
    # This uses offscreen rendering
    camera_image = physics.render(height=480, width=640) 
    
    # Then trying to use the viewer - this often fails
    viewer.sync()
    
    return camera_image

# Create viewer
viewer = mujoco.viewer.launch_passive(physics.model.ptr, physics.data.ptr)

# Run simulation
for _ in range(100):
    img = step()  # The viewer often shows blank or doesn't update

Confirmations

• I searched the latest documentation thoroughly before posting.
• I searched previous Issues and Discussions, I am certain this has not been raised before.

[yuvaltassa]

Please don't use dm_control.