Any idea how to achieve this effect?

Hi everyone.

I’m curious about how to go about creating the effects seen here.


In games like Deadlight and This War of Mine they’ve got this funky black effect that is mostly used to hide the cutaway portion of walls and floors. They’re in total darkness and not affected by any of the lights in the scene. They’ve also got this slight blur going on so the edges of the shadowy areas seem to bleed out a bit.

I’m guessing the blur is some kind of dof effect going on, right? But how would you create the shadowy areas? It’s not a texture far as I can tell, they’re completely unaffected by lights and as I’ve spotted the same effect on tons of objects (especially in Deadlight), not just walls and floors. I’m a bit stumped, I don’t see how they did it.

Can anyone clue me in?

Thanks a lot :slight_smile:

One way would be to create a texture of several such fuzzy-edged white blocks in the alpha channel, with the red, green, & blue at 0. Map one of these to a series of instances of quads which are placed over the gaps created when you reveal cutaway environments. Would probably help to fade them in quickly, as the facing outer wall fades, in order to prevent the hollows being revealed during the cross-fade. You get my drift?

You could probably use a post processing pass to do this. Anything nearer than a certain Z value would be replaced with black and also be written out to a mask. Blur the mask to get the blurry edges (or maybe just sample in a Gaussian kernel when doing the Z test and avoid creating the mask at all).

Michael Noland

So this is probably some kind of…custom post process effect?

Argh. Well if anyone knows how to go about creating something like this I would love to hear it.

Any ideas from anyone?

What I’ve done so far is apply an unlit material to the sides I want in darkness. That works okay, but as for the blurry, bleedy effect I’m not sure what to do.

For the blur maybe use Depth of field


Having done some assets like this before for an isometric project, all I did was have a poly plane covering the ends of the walls, and just applied a blurred edge texture to those planes. No need for post-processing or any fancy stuff. But when it comes to unreal engine 4, it’s more work that could probably be avoided by doing as Micheal Noland said, and Micheal’s technique described would probably be an unnoticeable difference in performance in UE4.

The best part about doing cut-outs is that there are several ways of doing them :slight_smile:

Actually doing this as part of a custom depth of field effect makes a lot of sense. DOF already has to do the distance calculation anyways, and at the maximum blur level you could just throw away color and replace it with black.

Michael Noland

Thanks for the tips guys, I’ll look into it and see if I can come up with anything.

I wasn’t sure about using dof at first. I would like to include graphical options that turn those kinds of effects off if need be. Disabling dof in this instance would reveal that part of the cutaway…but I don’t see any other way to do it really.

Thanks again :slight_smile: