Green screen sphere for exterior rendering


So here is something I am looking to do, but am having trouble figuring out the best way to go about it. I am currently working on an archviz scene that has a large outdoor balcony. Generally we would approach this with just using stitched images to wrap around the scene to give the illusion the building is in its real life location. This of course has its limitations.

Basically what I am looking to do is have a green material applied to a sphere around the scene instead of a typical sky material. The problems I am having currently are, if I just set a flat green material, the material only gets light from the directional light going in one direction, so half of it is very dark. If I set it to emissive, it shows up exactly like I want, but I get the side effect that the green light from the material gets cast down on the darker elements in the scene, especially on the metal, so I get bad green reflections on everything which looks really fake.

Has anyone attempted to wrap a scene in a green screen type material before, and if so, how did you go about it? We would really like to After Effects a bunch of stuff around our archviz project, but currently I am unsure of the best way to go about this. I can’t post the scene in question due to NDA’s, but I can make a sample if I am being unclear with what I am asking.

Thanks everyone -

Try setting your material up this way, this didn’s change the shadows for me but just check that any metallic surfaces aren’t reflecting green off them.

Yea, it gives the desired look to the sphere, but still getting the reflection on anything metallic which of course is a problem for an archviz scene. Is there anyway currently to shut down reflections from emissive lighting?

Anything in the scene gets reflected, due to the way reflections are handled.

You could however create a post process that takes the depth buffer and paints everything beyond a certain distance green. As post processing can take place after normal rendering you should be able to leave your reflections intact.

Isn’t screen space translucency a post processing effect as well?

This is the direction I thought I might have to head in after researching it a little. Any directions on where I can read up on creating something like this?

To do so you need a post process material. These can be placed under blendables in your post processing settings. This documentation page has some useful examples.

The material itself should not be too complex, take your scene color and key color and switch between them based on the values in the depth buffer.