How to create a normal texture file with gimp

[Aneirin]

Hello fellow modders,

I have already written several tutorials on our German forums, but now it is time for my first one on TWC

Our topic is, creating a normal texture file with gimp. As I recall, there are already several tutorials for creating one with photoshop, but none which explains to use gimp. So this is my turn.

For explanation what is a normal map, just check these tutorials here as well:
- http://www.twcenter.net/forums/showt...l-texture-file
- http://www.twcenter.net/forums/showt...ed-Normal-Maps

or have a look here:
- http://en.wikipedia.org/wiki/Normal_map

I suggest that you have already some knowledge how to use gimp and know where to find the right textures, if it should be required, just let me know and I will add a paragraph about this matter.

So what do we need:

- Gimp
- DDs plugin; can be downloaded here: http://www.plugins.de/plugin/dds/
- Normal Map plugin, http://registry.gimp.org/node/69

1. Step

Open the texture file from which you would like to create a normal map.
Then follow these steps:

- Flatten your image, under tab "image" -> "flatten image"
- Make the image transparent, tab "layer" -> "transparency" -> "Colour to transparency"
- Click "Ok" when this window open up:

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These steps need to be done to prepare the image, so we can create a normal map with the downloaded plugin.

2. Step

Your next steps are the following:

- Open the tab "filter" and search for "image" (hopefully it is the right translation, if not, let me know!), then go for "normal map"
- Now a new window pops up and it should look like this here:

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I use these settings, but feel free to try out your own way or settings
It doesn't matter, in the end you should have something like to this:

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Now in Photoshop we would manipulate the Alpha1 channel directly, but this is not possible with gimp (or I have not discovered it )
We need to use a layer mask instead.
So we head for Step 3.

3. Step

Now you open up the texture file one more time, so you have two open windows. One which contains the already manipulated file and one with the basic image.
Select the basic image you open the tab "colours" -> "apply threshold".
A window will open up, it should be this one here:

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Now you play with the controller, till most of the non-metal stuff is black.
I have this:

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Explanation:Everything what is now black, will be invisble later and everything which is coloured white, will be highlighted on the model later in the game.

So we need to take a pen with black colour and paint all the stuff which is no metal black. That mean faces and clothes alike.

In the end you should have something like this:

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As you can see most of all metal parts are white, these parts should be highlighted.

NOTE:
You might want to follow up the steps suggested by jurcek here as an alternative way.

4. Step

Now select the whole image with ctrl+a (strg+a) and copy it. Now go back to your previous image and do the following:

- right click on the layer window and choose "add layer mask"

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In the pop up window choose "white (full opacity)" and press ok.

- now a new "layer" appears next to the regular layer, the "layer mask", select it with a left mouse click

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- now insert your image and anchor your selection
- now right click on the layer window and choose "apply layer mask"; as you might notice the parts which we painted black are now invisible.

Last but not least, save your newly create normal map file as DXT5 with mipmap and place it in your correct game folder.

This is my result:

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Hopefully, I could answer more questions, than causing

But if you have any further suggestions or questions, feel free to ask!

Best regards Ned

[rafmc1989]

Aneirin,

thanks a lot for this tutorial.

This GIMP method is very nice, I'd say the "normals" got with it are nicer than the traditional ones got via Ps. It gives a new way of having units effects, and it's very fast too.
You can stress more effects and features on metallic parts when illuminated by the sun or other sources of light. A little but noticeable improvement!

Thanks a lot for sharing the knowledge!

[jurcek1987]

This tutorial has been a real life saver for me so thanks again . I'd just like to make an addition to step 3, the "shine" part of the texture. If you want to make HQ normals (like for example in Rusichi), the colours/threshold approach is not the best way, especially if the lightness on various metal parts varies. So instead of threshold, I use colours/desaturate/luminosity and then I also lower the brightness slightly until you get something like this (and of course also paint all the non-metal parts black):

before:

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after:

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in-game result:

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[rafmc1989]

Yes, the threshold may be stronger as effect, but still the good settings can enhance metallic parts in a good way, just finding the right combination.

But, the desaturate/luminosity ways can be alternative options too, gonna try them a bit!...

And, yes, this was a great tutorial for the ones using GIMP!

[Aneirin]

Thank you guys for the feedback!
Very appreciated!

I'd say it is a matter of taste. Depending on what type of 'theme' you are going for with your units

PS. Added the hint to Jurcek's advice