mujoco.MjData is not a constructor when using mujoco_wasm

[helxsz]

Intro

Hi!

I am a developer , I use MuJoCo for my drone research .

My setup

load the wasm from public successfully.

      const load_mujoco = window.load_mujoco;
        if (!load_mujoco) {
          throw new Error('load_mujoco not found in global scope');
        }
        
        // Load the mujoco instance
        const mujocoPromise = await load_mujoco();
        const mujocoInstance = await mujocoPromise;
        if (mujocoInstance.FS) {
          if (!mujocoInstance.FS.analyzePath('/working').exists) {
            mujocoInstance.FS.mkdir('/working');
          }
          mujocoInstance.FS.mount(mujocoInstance.MEMFS, {}, '/working');
        }
       let mujoco = mujocoInstance;
       let model = mujoco.Model.load_from_xml("/working/test.xml");
       let data  = new mujoco.MjData( model );

My question

here is the output

 MuJoCo load_mujoco is now available globally
 mujoco_wasm.js:8 MuJoCo version: 231  
Error loading scene: TypeError: mujoco.MjData is not a constructor

any idea what is wrong with it, is the mujocojs version too low, how can I get the latest mujoco wasm download

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.