Hi all!
First of all, you need to know that I am a noob with Unreal Editor 
Here it is my issque :
In Unreal Editor, I have created a virtual set with greenscreen. In front of it, I can set some 3D objects with reflection. I would like that these objects do not reflect the greenscreen but can reflect lights and other elements. Please find an overview attached.
I tried some solution but I did not find out.
Thank you for your help!
Simon