How can I achieve something like what you see in the video above with UE4? (fade in/out with black, death fade with red; preferably without using post process at all - needs to be really cheap on mobile)
Thanks!
P.S. Could be a regular unlit material of the give color, that renders in-front of scene (in the sense of sorting).
Make a UMG widget that is fully filled with a color and create an animation on the alpha to go from 0 to 1 to fade out, and another animation from 1 to 0 to fade in. Then just spawn the UMG widget when ever you want to fade in/out. Also adjust the UMG Z depth to make sure it renders on top of the rest of the UI as well (if desired).
Even easier and cheaper: there is a fade node in blueprints that allows you to directly fade a camera in and out of any color.
If you specifically want the stipple effect you’ll have to use a post process material though.
Do I need to use Matinee for any of that?
What about that pixelization effect, how can I achieve that?
Normally that would be best done in a post process material, but those are not available on mobile. Instead either a UMG widget or a plane in front of the camera will have to be used instead. The material itself can be super simple, here’s an example, simply animate the visibility from 0 to one to get the fade:
Easy indeed, thanks! 
So, how do I manipulate materials from BP ? (to enable fading in and out, and control fade in/out rate)
Material Parameter Collections could be a very easy way to handle this.
Alright, when I set Visibility parm to 0, I still see noise 
If I set it to any negative value, then I get 100 transparency, so to speak. I am not sure how to make it where Visibility parm varies from 1 to 0 and brings red from fully opaque to fully masked (“transparent”)
EDIT: Never mind. I tweaked noise texture so there are no 255, 255, 255 color and now it works fine.
One thing for sure - to make it pixel perfect (like in Wolf3D), I’d need to make a noise image of native resolution (which is non-power of 2) and that’s not a good thing. Is there a procedural (and super fast) noise material function in UE4 that I could use instead of image ?
I am guessing this is it Utility Expressions | Unreal Engine Documentation
The standard noise functions wouldn’t really produce the kind of pixelated noise you are looking for and they are very expensive for mobile use.
Luckily it’s noise, so it should tile pretty well. I would recommend simply tiling your noise texture to fill the screen instead.
