After spending a few months I have discovered my happiness in using Unreal Engine 4 than Icone 7!!!
For Iclone, there are more paid resources than for UE4. I wonder for example there is very few information about how to create  .iatm files.
These files can be helpful for developers to create a real panoramic scene. 
After searching for that, I am hopeless.
So, I think that I should stop using Iclone and try to produce interactive games/movies with UE4!!!
Sombat

Did you ask here?

Or check the manual, for example: https://manual.reallusion.com/iClone_7/ENU/Content/iClone_7/Pro_7.4/10_Scene/Atmosphere/IBL.htm.

Any environment in iClone can be save as an .iAtm file. There are many sources (including free ones) for IBL files that you can use in iClone.

---

Thanks for your link.
It was not very helpful.