Issues regarding reproduction of 'Learned_Materials.ipynb' and 'Synthetic_Data.ipynb'

[srijita-iis]

Hello,

The scene has been loaded properly, and I did double check with additional measures that there are 3 objects in the default scene, making the length of the number of scene objects 3 as well. But, when I try to run the two aforementioned notebooks, during the training I get an error stating that the indices of the object_id is -1, not within [0,3) and I am unable to train.
'object_id' is used in the trainable_materials class and hence, I am guessing that is where the isuue occurs.

[jhoydis]

Hi @srijita-iis,

I think that this issue comes from a specific combination of Tensorflow and Sionna.
Could you install these very specific versions and give it a try:

pip install sionna==0.16.2
pip install tensorflow==2.15.0

[jhoydis]

I have just pushed a fix that should solve the issue. However, you need to install Sionna v0.18.