Embossed text on glass - need help with the Normal Map

Support Materials and Textures
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#1

I’m trying to emboss graphics onto a glass bottle. I don’t have much experience so far in making my own bump and normal maps so using this as a chance to learn.

I’ve used CrazyBump to create a Normal Map with the embossed text. When using the normal map I get a lot of seams on my bottle model and odd areas around where the emboss is. I’ve UV unwrapped the bottle.

I’ve managed to create and use a bump map to emboss the bottle, but I don’t understand what I’m doing wrong with the Normal Map?

Screenshot 2020-04-17 at 11.07.27
Screenshot 2020-04-17 at 11.07.27782×448 174 KB

Bottle with embossing using Normal Map – there’s a noticeable band / block around the text area and the bottle surface is distorted.

Screenshot 2020-04-17 at 11.06.18
Screenshot 2020-04-17 at 11.06.18770×446 155 KB

Bottle with embossing using Bump Map

Please offer any critique or tips on how I can make the glass embossing look more realistic would be great. When the camera is Close Up on the emboss, the text looks quite pixelated.

Emboss-bottle-test.blend (2.0 MB)

#2

The bump map should have bigger resolution for a better gradient. It should also be set to Cubic for best interpolation. Apply some blur to it for smoother transitions. If this isn’t good enough or you get stepping artifacts, you need to create it at higher bit depth, like 16bit.

You forget to “unclip” the normal map. If you preview it, it goes black which is not expected normal data. Either turn off clip or use the alpha output to mix between the normal map node and geometry/normal output. The neutral blue/purple in the normal map isn’t exactly neutral. It’s close, not not exact. Collapse UV’s outside to a single point and move them to a neutral location, then use a new UV for any other effects.

#3

Thanks @CarlG

I’m a bit of a novice to this so would you be able explain further on a few things?

It should also be set to Cubic for best interpolation.

What does this mean/how do I set this up? Is a setting that should be changed in the material node?

Collapse UV’s outside to a single point and move them to a neutral location, then use a new UV for any other effects

Not totally sure what this means? Do you mean stack every veticie apart from the area I need to emboss? And have the stacked veticies say in the top left corner? On a netural colour?

Also I created the normal map through CrazyBump. Seems odd that the neutral colour isn’t completely neutral? Or is that normal behaviour?

#4

From what i can see in the Normal map, there’s usage of a big radius in the calculations of derivatives… It ‘bends’ a huge area (you’ll probably want to look at the Crazybump settings).
Apart from that, CarlG sugestions about clipping would solve the rest.

#5

The image texture node has a dropdown for interpolation. Change it to cubic (for bump maps). It will only help, it won’t do wonders.
Select the faces that is not the label, then resize them in the UV editor to a single point and move them to a neutral (0.5, 0.5, 1) color. Any face not in the label will use this neutral color as a normal modification - which should be none.
I can only guess that it’s because of the blur used in CrazyBump (I don’t use it myself), same as Secrop mentions.

#6

Thanks for the clarification @Secrop @CarlG