Accessing viscosity option inside python code

[prinshul]

Intro

Hi!

I am a graduate student at IITD, I use MuJoCo for my research on Multi-agent RL.

My setup

Hi

I am trying to access "viscosity" variable inside my python code.
https://github.com/openai/gym/blob/dcd185843a62953e27c2d54dc8c2d647d604b635/gym/envs/mujoco/assets/swimmer.xml#L3

My question

How can I access "viscosity" variable from the below code:
https://github.com/openai/gym/blob/master/gym/envs/mujoco/ant.py

Minimal model and/or code that explain my question

If you encountered the issue in a complex model, please simplify it as much as possible (while still reproducing the issue).

Model:

minimal XML

<mujoco>
  <worldbody>
    <light pos="0 0 1"/>
    <geom type="sphere" size="1" rgba="1 0 0 1"/>
  </worldbody>
</mujoco>

Code:

import mujoco
import mediapy as media
model = mujoco.MjModel.from_xml_string(xml)
data = mujoco.MjData(model)

with mujoco.Renderer(model) as renderer:
  mujoco.mj_forward(model, data)
  renderer.update_scene(data)

  media.show_image(renderer.render())

Confirmations

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

[prinshul]

Found it. Thanks!
self/env.model.opt.viscosity