Colour Look up Table problems on different machines.

  • Exactly as the title explains, when I put a colour lookup table into my map, even changing something very simple like the hue, that’s all, it might look perfectly fine on some machines, but completely ridiculous on other machines.
    Here is an example of what I am talking about. Same colour look up table, two different machines.

    I’m not sure of the specifics of how the look up table works, but at a guess, it contains data that the shader’s use in each pixel of the look up table to determine what everything looks like. That information is read by the graphics card afterwards and processed.
    And my guess is if that is how it works, then some graphics cards are reading things incorrectly.
    My graphics card is a Nvidia GTX680. I’ve also tested with Leynadix who has a GTX780, and it works perfectly fine.
    I have a friend who has a Nvidia GT640 which works fine as well.

    I believe the ones it did not work on, one was a middle/low end radeon, the other was a NVidia GTX570.

    In my look up table, when I create it, I am adding all sorts of filters to generate the right colours, so hue/brightness, levels, curves, brightness/contrast, exposure etc.

    I thought maybe that it was just one type of filter that creates something strange in the lookup table, but then I tried a very simple filter of slightly changing the contrast in hue/brightness.
    By doing so, it still resulted in this crazy orange super saturated, super contrasted colours on certain machines.

    The last thing I can think of is the post processing chain settings. I originally was using my own, which was a slightly modified version of:

    Now I just use the one used in most chivalry maps.
    Just to see if it was their computer, or my lookup table, we did tests. So I just used outpost or one of the other lookup tables, and it looked perfectly fine on their computer. So there is something wrong with my lookup tables :(

    I have no idea what causes this, but if few people have this issue, I wonder how many others have the same problem. So I am forced to remove the colour lookup table from my map as a result, until I work out why this is occuring.

    Here is how it should look:

    And here is what it looks like on another machine:

  • Looks like an issue with post process effects overall. Might be wrong about that but it might be good to check that your getting your lookup table stuff to look the way you want it to look without extra post process effects settings set manually elsewhere

  • Make sure your lookup table texture is compressed correctly, there is a specific LOD group for lookup textures too

  • Yeah, in photoshop, i’m just saving out as a png, it doesn’t allow me to just choose the “uncompressed” option though, which is what I want.

    The part that baffles me is that it works fine on some machines, but looks wierd on others :\

    Lookup tables add so much more life to a map, but this issue prevents me from creating that life safely without the fear that it will show up strange on the developer’s computers while testing, and the map being judged on it.

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