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Normal Map Banding

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  • jocose
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    jocose polycounter lvl 11
    Perna, what did you use to bake it and what were your settings?
  • EarthQuake
    Looking at some maps i baked both in maya and max(with default settings in both apps), Maya doesn't do any dithering, while Max does. This means in maya you'll get banding, in max you'll get noise. Generally neither of these will be apparent enough to care about tho, especially after you start texturing. The max one is probably ideal however.

    Heres some shots zoomed+increased contrast.
    maxmayadithering.jpg

    Baking at 2X, adding a small amount of noise, and resampling(size down) the maya result would probably work well.
  • Eric Chadwick
  • SHEPEIRO
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    SHEPEIRO polycounter lvl 17
    perna wrote: »
    Shepeiro, what you're talking about is the natural limit of 8-bit normal maps. That't not an "artifact" or something that can be fixed, hence it's not a problem.

    I've never run into a case of anyone who's had problems with normal map precision to the extent that they avoid using them. This is not something we've ever been requested or had the need to do.

    didnt say it was nessecarily a problem just something ive had to work around in the past...actually normally due to needing to use compression...

    and it is an - Artifact (error), undesired alteration in data, introduced by a technique and/or technology
    add a high gloss reflection map and thats when it really starts to becoming noticable, any compression aswell...

    dunno- never thought about adding dithering to the NM still not sure id use it for a shiney shiney car though ...moar polys is possibly cheaper in both memory and draw than uncompressed normal mapping... thats at least what i thought esp when i cant think of any racing game that employs normal mapped car paint shaders...well up for being wrong though
  • jocose
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    jocose polycounter lvl 11
    Hey perna thanks a bunch for posting all that. I just started using max more so I'm really int rested to try this out. Are all normal maps always stored as 8-bit images then? I didn't know they had an inherit range like that that. I suppose that makes sense though, but I thought it was just something you had to worry about when it went to compress it.
  • EarthQuake
    8bit per channel, pretty much every image you find (JPEG, TGA) is 8bit per channel, ie 24bit image or 32(24 + 8 for alpha). Not 8bit as in 8bit total for the image like a GIF. 16 or 32 bit per channel images are used to get higher precision, but not really used in games aside from HDR cubemap image based lighting in some.
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