3D Checkerboard texture has banding

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acasta69
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3D Checkerboard texture has banding

Post by acasta69 » Tue Jan 16, 2018 9:39 am

Hi,

I have some strange results using 3D checkerboard texture: there is a banding superimposed to the texture, and it is different between CPU and OCL engines. Path, tiled path or Bidir make no difference.
Plain colors or other textures (I have tried Blender clouds) do not show the problem.
I'm attaching a couple of images and the test scene.

Ale
Attachments
test03_sharp.zip
(129.15 KiB) Downloaded 77 times
PathCPU Sobol
PathCPU Sobol
PathOCL Sobol
PathOCL Sobol
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B.Y.O.B.
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Re: 3D Checkerboard texture has banding

Post by B.Y.O.B. » Tue Jan 16, 2018 9:50 am

Your ground plane is probably exactly at world origin.
You can either transform the texture a bit (e.g. 1mm in Z direction) or you can move the plane a bit.

@Dade: can we do something about this in the addon or in LuxCore?
E.g. move every object a tiny bit?

edit: on the other hand, the only texture affected by this is the 3d checkerboard texture.
Maybe I should just transform it a bit on export (but not every object in the scene).

acasta69
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Re: 3D Checkerboard texture has banding

Post by acasta69 » Tue Jan 16, 2018 10:12 am

B.Y.O.B. wrote:
Tue Jan 16, 2018 9:50 am
Your ground plane is probably exactly at world origin.
You can either transform the texture a bit (e.g. 1mm in Z direction) or you can move the plane a bit.
That was the problem, thank you.
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Dade
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Re: 3D Checkerboard texture has banding

Post by Dade » Tue Jan 16, 2018 10:39 am

B.Y.O.B. wrote:
Tue Jan 16, 2018 9:50 am
@Dade: can we do something about this in the addon or in LuxCore?
It is like having 2 coincident planes and having some ray hitting one or the other. It is a numerical precision problem. I think the only transparent (for the user) solution is a specific trick in the exporter or LuxCore adding an epsilon to the 3D mapping. I will add it in LuxCore.
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Dade
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Re: 3D Checkerboard texture has banding

Post by Dade » Tue Jan 16, 2018 12:37 pm

Dade wrote:
Tue Jan 16, 2018 10:39 am
I will add it in LuxCore.
Done: now the scene in the first post works fine.
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