If this has been posted in the wrong section, please let me know.
I dont know about the rest of you, but as a graphic artist I am rather addicted to the layer blending modes of Photoshop. So much that I kind of missed their presence within UDK. Sure, the basic effects (such as multiply and additive blends) could be made rather easily, but others were painfully lacking in my opinion.
So instead, I did some research online and have now got myself a set of custom blendmode tools for use with the material editor. Far from perfect, that is true (I am not a hardcore programmer nor really proficient with UDK, so I made some Frankensteins of sorts), but still very usable. If you have made a better version or improved on mine, do not hesitate to share it .
And here they are! I am sure that there are some graphic artists out there who could use a blending mode widget in UDK without having to create extensive networks of widgets.
There are a total of 21 blending modes (with one mode being customizable). Each mode takes a base input and a blend input. The ones named with commutative can have their blend and base switched.
I have included two materials; the one named custom contains all the shaders above and a customizable HSL shader. The HSL shader works a little bit different; it also comes with three constants. These are to switch between the RGB channels of both the blend and the Base image, to create different effects (0 is the channel of the base material, 1 is the channel of the blend material). The goal of the HSL shader is to emulate the "Hue", "Saturisation", "Color" and "Luminosity" blending modes in Photoshop. Due to the nature of converting RGB to HSL and back, I think this is pretty much the most demanding blend though.
The custom contains all the shader data summarized within a custom code widget. I am not sure how heavy it is to produce at realtime, but I do know that I couldnt get some effects to work otherwise (or not as clearly).
The widget based contains all the blending modes I created through widgets. It contains the obvious easy ones and some more intrinsic ones. The more complicated versions however are only available through the custom widgets.
To use one, just copy/paste it into your own. I have mostly tested it using the PostEffects chain (using a material effect), but so far I am liking the results.
As for the sources I used to create the blending modes: