Well, I continued digging to see if I could find what was going on here.
Maybe I did miss it somewhere in the UE5 Lumen Documentation, or this is just a normal behavior when using Raytracing.
In any case, here a quick video that demos what is going on:
I was thinking to do some screenshot to help this little description but it has been more easy to add a checkbox with its function to my WIP Lookdev Tool and just record a quick video to showcase what is going on, for those like me, that could be “confused” about what is going on with these lighting channels.
Basically, Ray Traced Shadows ON will cast shadow from the “Channel 1” Objects over “0 Channel” Objects. (and also will make Volumetric shadows not to work) even if it is set only to affect “Channel 0”.
I do love this new Lumen, also because it has been made in a way that does not need Raytracing Hardware to function in a decent way. I hope EPIC can continue improving this and hopefully bring us back the Lighting Channels the way they behave with no raytrace shadows, but… with raytraced ones ^_^.
*Featuring Allen Grippin´s - Great “Cthulhu” Model
Special thanks to him for letting me showcase his model in the future promos of my tool.