Author Topic: Noise map banding at small scale  (Read 4473 times)

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Offline Gestalt

Noise map banding at small scale
« on: November 26, 2020, 09:16:14 am »
Hi,

Has anyone had this problem or know how to solve it? On a number of parts I get a banding effect with the noise map applied.
The below image shows the isolated noise map and you can clearly see the issue (different size banding on different surfaces).
Data came from Rhino import, tried custom OBJ import also. Normals ok. Keyshot V9.3 Pro, same issue in GPU or CPU mode.
Same issue wether Fractal or Texture noise map.

Also attached is the 'noise map as a bump map' illustrating the stretch and compression of the noise map that creates the bands. Clearly a mapping issue no?

Mods please let me know if I should report this as a bug?

Thanks,
« Last Edit: November 26, 2020, 10:52:39 am by Gestalt »

Re: Noise map banding at small scale
« Reply #1 on: February 15, 2021, 01:01:17 pm »
Hi!
I am facing similar issue!

Re: Noise map banding at small scale
« Reply #2 on: February 15, 2021, 03:06:59 pm »
The issue surfaces when using low scale values and high bump values for noise texture.(making grainy plastic material for example)
I have exaggerated the issue in the attachment. Noise scale 0.1mm, depth 1.  Issue is not noticeable for depth values under 0.2
Re tessellating and  recalculating normals did not solve the problem.
Issue arises mainly on imported NURBS geometry. Inbuilt keyshot objects don't seem to show the same problem unless the sale value is made extremely low.
Changing scene units, Translating and rotating texture did not help.
Issue happens in GPU and CPU mode.
« Last Edit: February 15, 2021, 03:10:36 pm by tony_blenderman »

Offline Nexus

Re: Noise map banding at small scale
« Reply #3 on: March 04, 2021, 02:15:25 am »
Hello everyone, have similar problem. Keyshot 9 version.
Please text, if you solve this bug.

Re: Noise map banding at small scale
« Reply #4 on: March 04, 2021, 02:21:27 am »
Hi Nexus, I found a workaround by translating and rotating the noise texture map. No specific angles or translation distances. Really annoying but fixed the problem well enough. Also please avoid using extremely low noise scales.

Hope that helps

Offline jordan

Re: Noise map banding at small scale
« Reply #5 on: May 24, 2021, 06:09:05 pm »
Has anyone found a solution to this problem?

Happening in Keyshot 10 Also. Rotating the texture around feels like a band-aid approach to a potential core problem.

In the screenshot you can see the problem is happening on the bottom half of the object but not the top half, with the exact same material applied. Weird.

Re: Noise map banding at small scale
« Reply #6 on: May 24, 2021, 07:51:43 pm »
Hi Jordan. Try the bandaid approach! Also, do not go too low on noise scale value. Cheers.