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Custom Chroma Key inside UE4

Hello world!

I am trying to key in some live action in the Elemental Unreal demo. I have the camera track already inside of unreal. And I already have the talent keyed out.
The issue I am running into is when I want to create a green screen inside of the unreal 4 elemental demo I am getting a ton of spillage onto the environment surrounding the green screen. My real question is, is there a way to create a material that does not interact with any other materials surrounding it?

In a word: No. It’s probably the post-processing doing most of that, but you also get it in the screen-space reflections too. There’s nothing you can do to stop that unless you want to radically change how the scene looks. Your other option is to use a post-process material that uses the scene depth to make that green screen itself, but you’ll have to change the parameters a lot to put it in the right place if your camera moves a lot.

That material also looks insanely emissive, can you show some different shots of your set-up? The material and how it’s applied in the scene?

You ought to be able to use custom depth on your green screen object, and a post-process material that just writes green for those objects:

Cheers,
Michael Noland

the material is simple, just a vector 3 (0,255,0) attached to the color node. and then a value of 1 assigned to the roughness to minimize reflections

Alternatively is there a way to output from the ‘diffuse color’ because there are no reflections in that window. and then I could match it with my footage

Apply a blendable to the GlobalPostProcess and then create a new material that’s a post process, in the emissive channel assign a sceneTexture node to it and choose diffuseColor/baseColor from it’s ID channel.
then when you render out of the matinee it respects that in the renders.

That’s why then, your vector 3 should be 0, 1, 0. The values go from 0 > 1 for full colour. Anything above that starts adding to the bloom.