Author Topic: Noise in normal map  (Read 3766 times)

Hi. My exported normal map has a noise even there are no layers in the project. Any idea whats happening or is it a bug?
Last Edit: December 25, 2018, 05:42:48 am

This is the dithering automatically applied to normal maps at export to avoid banding and other artifacts.

So that means I can never have a glass with 0 bump. How can i disable the dithering?

There is currently no way to disable it unfortunately.

Okay. How can i create material which has zero bump

Setting your normal channel to 16bits and exporting in a 16 bits capable format like png should bypass the dithering.

Since my models are game models, I cannot use 16 bit textures

Since my models are game models, I cannot use 16 bit textures

You can either let Painter do the dithering for you at 8bit, or take the 16bit textures and load them into Photoshop, and do your conversion to 8bit without dithering.
Last Edit: December 28, 2018, 04:15:42 pm

Is this what the dithering does?

Even in 16bit the normal maps have this noise on them, so I can never have clean smooth looking textures, they all look like noisy surface.

sorry image upload isn't working too well.

Is this what the dithering does?

Even in 16bit the normal maps have this noise on them, so I can never have clean smooth looking textures, they all look like noisy surface.


Your normal maps from painter look like the above????

when you use levels to look at the difference in values this is the noise that substance painter adds to normal maps.
If this is the "dithering" it should be optional, because you can't really fix the normal maps once this is exported.

I did provide the solution above. You can take your 16bit png and output it to 8bit without dithering. The problem is that you're going to get noticeable banding without the dithering at 8bits which is why this is done. (more so apparent with different 'materials' than others.)

I took a plane and baked low as low to generate a flat normal map. Then I exported this map as a 16bit PNG, there is no dithering:



Now if I export 8bit png I will get dithering as stated prior, this is done on export.



Now if I take my 16bit png and convert it to 8bit I don't have any dithering:



Read up on this more here: https://polycount.com/discussion/148303/of-bit-depths-banding-and-normal-maps

Also, I don't get your issue with 16bit PNGs.
Last Edit: April 11, 2019, 06:05:04 am

Using 16 bit does have no dithering, I was wrong. But i still have some cases where 8bit no dithering is preferable, or other cases where only exporting the normal map at 16bit would help. so it would be useful to be able to turn dithering off and also bit depth per map.

P.S. I don't have original files to for some normal maps that are 8bit, so they can't be fixed in Photoshop and the dithering probably looks worse than the banding would.

You'll have to make a request for a feature to disable dithering on 8bit. I only know of taking the 16bit and doing manual conversions to 8bit without dithering as it's now a forced feature upon export.

You would be looking at suggesting an export option to toggle it off or on.

https://allegorithmic.uservoice.com/forums/261284-substance-painter