How can I render a spotlight hitting a transparent wall?

I may need to reword the question… I am matching a wall in a video with a non-renderable plane mesh that’s supposed to catch a spotlight light. How do I get the light to show when rendering? I’m using 2.80.

Thanks guys!

This “Eevee shadow-catcher tutorial” should give you some ideas:

In this case it would of course be a light catcher, but I think that the essential technique for the use of nodes are about the same.

I’ve got a pretty good lead (I think), from Chris (
Basically he says: “…the shadow catcher doesnt work like this, what you need is the emission pass, youll need to place the plane on the position of your wall and activate the emmision pass from the cycles render settings, you can the extract the pass from the render layer node and use it to composite the emmission onto your footage. you should be able to extract the shadow pass too so you shouldnt need to have a seperate plane for both shadows and emmission”

But be careful to note that “emission” works very differently in Eevee versus Cycles.

This is a case where it does matter very much which renderer you are talking about, similar though they (in some ways …) are.

That’s a very good point.
Thanks sundialsvc4 :slight_smile: