Friday, April 6, 2012

UDK Bleach Bypass Post Process

I have just built a bleach bypass post process shader for the UDK. It is based on the material editor node system, so there is no hlsl at all. The performance impact is roughly 10-12% - tested on a low end GT520 gfx card. Material paramters allow to adjust the overall effect intensity, brightness and desaturation.

What the bleach bypass basically does is creating a desaturated copy of the scene and overlaying it (this means screening the bright areas and multiplying the dark ones). This will result in a scene with less saturation and a higher contrast. For further information read trought this:

Material Setup


  1. this and the cross processing are fantastic!
    i'm tryng to do in udk but i'm noob, it's very difficult for me.
    could you help me?


  2. Hi,
    first of all you should trough the UDN material page(s) There is also one that specifically covers Post Process Materials:

    What I did is "translating" a usual Photoshop workflow into the material editor nodes. I will add a material setup screenshot later on.