PP2014 'Banding' in Atmosphere



  • Hi folks,

    I have always experienced this and, frankly, I've reached the point where I'm fed up with it and want to stop it from happening completely, instead of 'fixing' (bodging) it in post.

    Here is an incomplete render I'm currently working on. Apologies for the weird dimensions etc, it reached this far and I killed it, due to the 'banding' in the atmosphere.

    I'm using a single spot and an atmosphere shader. I've tried increasing the step size, but all it seems to do is take ages longer to render, without giving any noticeable improvement at all.

    This issue really gets ugly after editing the image in post with such things as sharpness etc, so I desperately want to get rid of it.

    Any ideas, please?

    0_1487534983363_Untitled.png



  • Also, if anyone has any tips on how to get Annie's hair looking more realistic, please let me know. I can post a screenie of the shader, if needed. I'm thinking it could do with some SSS in there or something, but I'm not sure. It looks a bit solid and dead to me, given the severity of the lighting and shading everywhere else.



  • I'm not sure if I get this right.

    The problem is the darker face, I assume? Can you post the shader you use for the atmosphere?

    About the hair shader, I suggest you have a good read here:
    should hair be anisotropic


  • Poser Ambassadors

    If you're pushing a gradient like that (8 to 22 in individual steps, forming wide bands) you're suffering from the inappropriate use of 8-bit data.

    You need to export your render in EXR or HDR, where the full dynamic range is recordable. Then when you post process, you're working on 32 bits of data instead of 8, and your image editor will have good data to expand when pushing these gradients around in the color space.



  • Thanks for the replies!

    Here is a screenie of the shader, it's very basic.
    0_1487540126344_picture001.jpg

    I'm using an all-black dome for the background.

    I will try exporting in EXR and HDR, but I think it would be prudent to mention that the render appears exactly the same within Poser, prior to exporting, so would this point to a problem within Poser?


  • Poser Ambassadors

    Your screen is 8 bit. It will appear how it appears when reduced to 8 bits because that's what your display does, unless you have one of those $15,000 video and monitor combinations that does 14 bits.

    Meanwhile, we're talking about how you can MANIPULATE an image. In the end, you WILL have to VIEW it in 8 bits, but that step should be put off until the end.

    If you manipulate the gradient with 32 bits, then you will not have banding until the end, and that final banding is unavoidable.

    Your monitor only has 256 levels of any color component.



  • Ah, I see! Well, thank you very much for the info there! :)


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