How to use composite with type="cable"

[tadashiK]

Hi,

I'm trying to use MuJoCo for cable manipulation. I'm looking for some help with the following demo xml file for using composite with type="cable".

https://github.com/deepmind/mujoco/blob/8696247f9d6baa1a0feb9103640bd41c8a35379e/model/plugin/cable.xml

It seems to me that the demo xml file does not compile anymore due to version updates. When I tried compiling this xml file, an error appears and says

ValueError: XML Error: Schema violation: unrecognized element
Element 'plugin', line 4

So, it seems <plugin ...> does not seem to work anymore. After removing the <extension> block, still I got an error saying

ValueError: Error: unrecognized plugin 'mujoco.elasticity.cable'
Object name = B_first, id = 1

Now, it seems that the plugin name has been changed, or the plugin for cables do not exist anymore. After removing <plugin plugin="mujoco.elasticity.cable"> block, the xml file finally complies.

However, now an issue is that it is unclear how to change twist, bend, and so on. The mujoco xml reference page does not explain how to change those attributes.

Can anyone help me with this? What is the current appropriate way to use composite with cable now? FYI, this problem seems to happen when MuJoCo was installed via conda or pip.

The following is a link to colab that replicates what I did: https://colab.research.google.com/drive/1tOP38GGEe6xyzKkhhBOgudmn69PDck87?usp=sharing

[tadashiK]

Sorry, the following closed issue is obviously related. I closed this issue and continue discussion there.

#723 (comment)

[tadashiK]

Because there is no response in the above issue (723), please let me reopen this issue and ask the question again.

[quagla]

Just tried your colab and it works fine for me. Could you make sure you are installing the latest MuJuCo?

[tadashiK]

Ah, you are right... One day after opening this issue, v2.3.3 was released. I confirmed that v2.3.3 does not have this issue while v2.3.2 does. Thanks!