I get banding artifacts when using displacement (the output node one, not the modifier, and it is set to "Bump", not "True") in Cycles.

At first I used a 8-bit greyscale texture and I expected to get banding, but then I blurred the texture in the Compositor and saved the result as a full-float .exr file. I then replaced the 8-bit texture with the .exr file. So it should have more than enough information to avoid banding and the blurring should also have at least reduced the sharpness of the banding, if not completely removed it because the steps were pretty close together.

Note: I made a mistake creating the texture, which makes the question unnecessary. Sorry.

That doesn't happen though, and I'm wondering why that is and if anyone has a solution for this. Here I found a similar problem, but there the question is how to save .exr-files. That's not my problem.

Also, this answer could be relevant but I don't find those settings for a texture that is used as a node inside of a cycles material. I also think the problem there is slightly different because the modifier behaves differently.

This is an example of what the result looks like:

enter image description here

Thanks for any help.

  • $\begingroup$ I'm pretty sure that all you did was save the noise with more precision. It does look blurred though. $\endgroup$ Jun 11 '14 at 10:50
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    $\begingroup$ perhaps try save it as a 32-bit image, then reopen that and blur it, and save it again. The problem could be that the blurring function is working with an 8-bit and thus outputs and 8-bit, and saving it as 32-bit is doing nothing at all. $\endgroup$
    – Greg Zaal
    Jun 11 '14 at 13:37
  • $\begingroup$ Greg Zaal: This would make sense, and although I can't reproduce that happening, something like that seems to have happened. Definitely a user error in creating the texture. Thanks. $\endgroup$
    – JulianHzg
    Jun 11 '14 at 15:11

I'm pretty sure that all you did was save the noise with more precision. I think if you blurred it enough to get rid of the noise then you will have nothing but a wavy cloud of a displacement.

Try to make your depth map using blender modeling/render tools, and then use that result for Displace.

Here's a set-up that I found on a BlenderArtists.org thread that should help you along. If you have any questions please ask. I'll update my answer tomorrow with a bit more detail on how this works. I just thought I could get you started with this little bit for now.

Once you have the setup right, you can just do a camera render and save it as an .exr, that will be your high-precision displacement map.

enter image description here

  • $\begingroup$ I know how to bake a displacement map, the reason why I'm using an image texture for the displacement is because that is the form in which I have the information available. $\endgroup$
    – JulianHzg
    Jun 11 '14 at 14:20
  • $\begingroup$ Well, for anyone who ends up here and who does not already know this, I should also add that displacement textures should be changed to Non-Color type. This is the same for .exr normal maps. $\endgroup$ Jun 11 '14 at 18:35

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