Proper way to add a Background plates in Corona?

[duke]

Hi,
I've got a problem with my BG plates in an interior I'm doing at the moment. They come up white when seen through the windows. If I hide the windows I can see the BG again. The BG plate has a CoronaLightMtl with all "Visibility" checkboxes on and "Multiplier" of 1.0. The strange thing is that if I apply a shadow catcher material then I can see the the background just fine through the windows, no longer white. So what's the proper way to add Background plates in Corona?

[romullus]

Do you apply background image via enviroment overrides or via mesh plane?

[duke]

Mesh plane.

[romullus]

Try to do like in this topic: https://forum.corona-renderer.com/index.php/topic,5921.0.html Is this working for you?

[duke]

Thanks, romullus, this fixed it! However, I didn't have to put the material in Ray Switch material. I just enabled Receive and Cast shadows in object's properties. Why does disabling these make the BG plate invisible through refractive objects? Is this a bug?

[romullus]

Not sure if this is a bug, it may be, but it's advisable to go RaySwitch route instead of right click rendering controls in Corona, AFAIK. The fact that you didn't plug background plane map through RaySwitch material, means that that plane contributes to lighting of your scene, which more often than not is undesirable.

[duke]

One more question. Why do I need to put the material in a Ray Switcher? If I disable "Emit light" my BG plane doesn't emit light.

[romullus]

But it still blocks light and rays are bouncing from it. So it affects your scene lighting and processing time in negative way.