DALII

Finally! Whole thing bothered me quite a while now, but I'm quite certain now: We're using Corona Render including Corona Sky. It seems like the material that appears after I click your script is the internal material for the Corona Sky object. After the material is visible, I can change something inside the Corona Sky object and the changes also happen inside the material. When I delete the material, the viewport background changes and the sky disappears. Looks like the material is solely for the viewport background, because the rendering still works - it is only affecting the viewport. Quite funny: 'Delete Unused Materials' deletes the material too and the background disappears. Adding a new Corona Sky works and the sky is visible again ... I guess your script digs a little too deep into the material hole in that case. Nothing is lost there, but I imagine it could be frustrating if you don't know what is going on. I've created a new comment in case someone else is looking for that behavior

In this regard: It maaaybe wasn't that simple. If I open the template scene, delete unused materials and then use your script, no additional material appears. But if I open the template scene, delete unused materials and then save the scena as my new template scene, the same happens again if I open the new template and use your script afterwards. Of course it won't happen if the unused materials are deleted before, again. Really strange problem, but it has definitely something to do with our template scene. But, to be honest it is no big deal to delete that material once. I don't want to bother you with that any further

Did a quick test: This only happened with our new / template scene. In a blank new project everything worked fine, as it should be. It looks like it is fixed, if I use 'Delete Unused Materials' before executing the script the first time. Maybe there is an old material somehwere unused in the cache / system / or whatsoever (?) Seems fixed now! Thank you for pointing out that it had to be on our end!

2023.1.3 works for me! But it looks like the plugin always creates a material called 'Mat' with a Sky texture applied when it is used the first time in each new project. Kind of strange behavior. After that I can delete the material and it won't appear again. Anyway, really great little plugin to work with in big scenes! Thank you!