Screen Space Gradient material?

I’m trying to have gradients take the place of textures, the end goal is to have a number of different objects in a scene all seem like they’ve been masked out and there is a solid gradient behind them.

The game Killer 7 is the best example of the effect I’m going for (the purple to grey in the first, and then green to blue in the second)

I’ve found this tutorial for making something similar but the gradient is only local to the object, i want the gradient to stretch the screen space and always look the same from any perspective.

[Tutorial I mentioned] 7.jpg screen 3.jpg

You would (probably) have to use a post-process Depth in order to achieve this

The items are still shaded though, so it’s a little more than just applying a gradient over the post process.

Unreal actually just recently posted a tutorial on their YouTube that may help give you some ideas to achieve this: