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Problem with spec maps - black highlights

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    Problem with spec maps - black highlights

    So I've encountered a weird effect (error?) that is only present within one of my materials... For my spec map I have very dark areas, obviously because I don't want those parts to be shiny. But instead of not being shiny, these areas receive highlights that are completely black.



    Anyone have any idea what's going on?

    #2
    Is your specular texture a greyscale (8 bit) texture?

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      #3
      All of my textures are saved from Photoshop as 24-bit Targas, but this is the only one I'm having trouble with.

      Doesn't the regular "specular" input refer to specular color, and thus can take a colored texture? I have another material that uses a colored spec map for red-tinted highlights.

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        #4
        You are correct. Specular maps connected to specular port are (or rather should) always be 24 bit color maps - in difference to specular masks that can be 8bit grayscale images.

        Does the same problem exist in the game world (different shading) and does it exist if you disconnect shader tree from the specular port?

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          #5
          Disconnecting the spec map does fix the problem (but of course knocks out my spec parameters!), so I'm pretty sure it's an issue with my spec texture, I just can't figure out what.

          Haven't tested it in game yet, I'll post again after I have.

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            #6
            Yea I just tried it out in a quick test map, it still gets those weird black highlights. I tried disconnecting the normals thinking maybe it was a bad normal map but that didn't fix it, so I really have no idea what's causing the problem.

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              #7
              My guess is that it's normal map related - I had a similar problem in the past but not in realtime lighting mode, thus it's a blind guess.

              - connect a constant color shader to specular port
              or
              - connect a constant color (0,0,1) shader to normal port

              and see the results. This would be the simplest way to find out where the problem is.

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                #8
                I agree with mslaf about it possibly being normal map related. The normal map in the screenshot is way too blue and doesn't seem to be having any affect. What program did you use to make it? Keep in mind that UT3 uses x+ y- z+ coordinates for normal maps. Depending on what app you used you may have to manually flip the green channel of the normal map.

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                  #9
                  Even with a constant 3 vector set to 0, 0, 1, the black highlight still shows up. I'm pretty sure it's an issue with my spec map, plugging in a constant gets rid of the weird effect, but of course limits my control of the spec properties.

                  Also, there's nothing wrong with the normal map. It was generated using Nvidia's normal map filter for Photoshop, with X+ Y- Z+ coordinates. Normal maps always show up oversaturated in the material editor.

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                    #10
                    <random guess>Does the spec map have any values below 0?</random guess>

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                      #11
                      I don't recall normal maps being too overly saturated in the Material Editor. make sure you are using one of the normal map compression types when importing. It sets some properties that are important for normal maps to function correctly. Not saying that is causing the black specularity...just saying in general.

                      Maybe you could post the spec map (and normal map too perhaps) so someone can take a closer look at them. Screenshots or a listing of the texture properties wouldn't hurt either.

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