Normal Map Faceting Errors

Support Materials and Textures
1

Hi there, I came across this odd issue with whilst trying to create a rough material:

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The object is quite simple and there is nothing connected except a normal map. The facets seem to show regardless of what mapping I use and Smooth Shading has been enabled with a subdivision modifier so I’m not sure what is causing this issue. Any help would be appreciated.

thanks very much :slight_smile:

2

Hi there!
Well, a few things to mention (although not sure about the aim of the work):
1, apply object scale and search for duplicate verts (merge by distance).
2, set shade smooth, I would rather pick object coordinates.
3, Noise roughness is max 1 by default, not sure why 20 would be necessary, probably try it with roughness set to “1”.
Then
4, textures tend to glitch if set too high scale, not sure why, it’s a Blender thing maybe, then you see radiant white grainy lines usually… When noise is above 2000-ish, but musgrave as well, with high lacunarity. So anyways, definitely something about high scale.

So try setting the mapping scales to 1 only, noise to 1000, and roughness to 1 with all the above points.
If it won’t help, kindly reach back😊

1 Like
3

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Unfortunately its still happening with the object. My aim is to just make a Matte material using Noise as the normal. I know I can use it as a roughness map as well but Im just wondering why this shading issue is happening, Im a bit boggled as its such a simple node setup yet its producing these odd facets

4

Interesting… I found this bug report that appears to be the same issue:
https://developer.blender.org/T74367
It looks like smoothing artifacts were fixed only when using object or position coordinates. Try one of these and see what happens.

5

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They seem to result in the same thing, This is very Odd, I cant think of anything else that may cause this. It has the same behaviour as well whether I apply subdivision or not. I find this so strange

6

It seems there still is issues with bump in Cycles.

However the values you are using are surely not helping. It’s hard to tell when using only a flat bump, but if you use the same texture as adaptive displacement, you will get something like this:

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This is the default cube with the default displacement strenght. Your bump is trying to calculate the shading of giant spikes on a flat surface. If you reduce the strenght more, you will notice that at some point, the facets stop being visible. That’s because you have reduced the bump to a height that’s accurate for the small details you are trying to create.

Of course, it will look a bit flat despite being at an accurate strenght, but that’s the way flat bump is. Talking about adaptive displacement, it does a much better job at the same effect, if your scene allows the performance hit:

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This is the same displacement, but with strenght adjusted. The render settings are set to displacement only.

If displacement is not an option, what about trying normal maps?

7

I have used a lot of bump and normal baking recently, and have not met this specific issue.
Is it possible to share the .blend to take a peek? :blush:

9

Hi etn249, Its not that the object is flat, Im not trying to displace it at all. The issue is that with a bump map, the object looks like it has Flat shading on, even with it set to smooth Display and having a subdivision with 3 Levels Active.

10

I don’t mean the object is shaded flat. I mean the bump itself is a flat rendering technique (in the sense that it doesn’t actually displace the surface), which means you can easily set the bump value to something huge without noticing and the shading doesn’t react well. Of course the harsh borders are a limitation/bug of Cycles and I would also like it to react better than that.

I was suggesting using actual displacement because it’s a workaround that actually does what you are trying to do (I am aware it has worse performance and is not for every scene).