Participating Media is not working

[Ghiraa]

Hello, I am trying to fill a box with water to see how light scatters. Although in the documentation there is an example of how to add an interior attribute to an obj shape (https://mitsuba.readthedocs.io/en/latest/src/generated/plugins_media.html):

Mine is not working, resulting in this error:

This is my code:

Thank you!

[ziyi-zhang]

Hi, the value of key interior is the string "water", not the homogeneous medium defined above.
You can for instance do

water = {
  'type': 'homogenous',
  ....
}

'box': {
    ...
   'interior': water
}

[Ghiraa]

Hi, if I do this it complains that water is not defined.

[Ghiraa]

nevermind, I solved the issue