UDK - Isolate mid-gray color in material editor

whynot

Quick question for you polycounters:

Is it possible to isolate the mid-gray color in this image?



I've used power nodes with exp to isolate the white pretty easily:


but now I want to 'subtract' the white and keep the mid-gray. I can't use a OneMinus to invert either, because I need to keep the black border, black. This is what happens:


*EDIT* Is there no way to take all the values from 0.5 to 1 and make them 0 while leaving everything that is 0.49 to 0.01 alone?

For the curious.. I'm trying to use the green channel in my image to control 3 different areas of my button. I want to be able to have an access granted area (top left), access denied (bottom left) and the main area to the right. All being able to be controlled through kismet.

Thanks in advance,
Tony.

whynot

Got it working ...kind of:


Looks like the way I'm doing it creates nasty edges on all of my 'masked' off areas, especially when it's all glowing. There has to be a better way to do this.

I'm trying to go all Tor Frick on this texture and it's not really working out.. I'm going to chalk it up to my noobness in UDK - 2 months

Any help would be appreciated.

Thanks,
Tony.

imbueFX

Just taking a quick glance at this, may an IF expression would be a better solution for this? Or just lerp between states?

whynot

Thanks imbueFX! Grats on getting your stuff up on 3dMotive BTW.

So that really simplified the chain, but I'm still having issues around the edges:


Maybe it's just not possible. I don't know much about it, but is this a mipmapping issue?

Thanks again,
Tony.

imbueFX

Hrmm could be, you can mess with the compression settings of your texture to help narrow it down. If you set to uncompressed and disable mipmaps, does it change? That will help narrow it down to where the problem lies. I can take a look if you post a package, it's hard to say just by looking at a screenshot versus being able to get in there and change settings.

And thank you!

whynot

Thanks for all the help so far! Here is a link to the sample I'm working on. It's really simple, because I'm just trying to get the principles down. I reimported the texture with no mipmaps and it helped a bit, but if I pump up the red, green and blue colors they still give the same effect.

https://dl.dropbox.com/u/59589536/MiniDisplay_Test.upk

passerby

use the "IF" node.

http://udn.epicgames.com/Three/MaterialsCompendium.html#If

Money

Perhaps you could give it a try with material masks since you can control the direction and percentage of the screen. You essentially mix those Solid Mask parts (see bottom of the page). In the case of square/rectangle masks you wouldn't need a texture mask in the first place.

http://udn.epicgames.com/Three/MaterialMasks.html

Ace-Angel

Change compression to VectorDisplacment.

LoTekK

Or try TC_Uncompressed. The fringing is more than likely due to compression, so uncompressed should alleviate/eliminate that.

JamesWild

Better idea, much cheaper and easier:

Split your mask texture into solid areas of red, green and blue.

Import it as a tiny image with no filtering, UI compression (should require 4x4, tops)

Multiply your three areas with the three channel intensities.

EDIT:

http://www.smallfiles.org/download/1497/JamesWild_Masking.upk.html

Harbinger

If you want to keep the edges of that mask nice and clean, try changing the Filter setting on your texture properties from Linear to Nearest.