Normal Mapping in Layers
I’d like to share with you guys a normal mapping technique that achieves results that approach those of the normal maps on the Rusichi textures that most of us love so much. A lot of credit for the development of this technique goes to my friend Dome from the Magyar mod who showed me the basic principles on which my way of doing things is based.
The main advantage of this technique is that it allows for very clean normal maps that show only the surface details you as the texture artist wish to show and in turn allows for greater three dimensional affect. In addition, no special programs are required. All you need is Photoshop and the Nvidia normal map plug-in. (You will however need keep your original textures on layers in your PSD files rather than consolidating them.)
Here is the texture I intend to demonstrate this technique on and the resulting normal map:
You can clearly see which piece of fabric lies over top of which and the wrinkles in the clothing are unobscured by the textile pattern.
Okay to proceed, it’s first important to understand how the Nvidia filter works. Dome discovered that the Nvidia filter basically makes every thing colored or dark to appear more raised and everything white to be set further back. This is a problem because we naturally highlight to show raised details on our textures. If you use the Nvidia plug-in with the textures as you create them the normal maps you make will be working against what you created and will thus obscure some details. It will actually set highlighted details further back. Because of the old concave/convex eye-fooling trick with light, you may not notice this too much, but it’s better to have your normal maps and textures working together. Unless the raised details of a particular texture are the darkest, it is best to invert all textures before applying the Nvidia filter. Because it is also hard for you to judge color saturation with your eyes it is also best to desaturate your textures. That way you know that darker equals raised and lighter equals set further back. With color taken out of the equation, the scaling of the Nvidia filter will also be more consistent layer to layer. This may all seem complicated to some, but trust me, it’s not once you see me run through the process.
Create your background:
Your background should be a light color before using the Nividia filter. I usually use black backgrounds so I simply invert them:
Image > Adjustments > Invert [Ctrl +I]
And then I run the Nvidia filter:
I use the Average RBG stetting and with the scale set to 5.5. You can experiment with other scales as most of you already know - the greater the number, the greater the depth difference. Of course the background is all one color so there is no difference here.
Remove all layers but the lowest:
In this case I’m starting with the mail because Muslim soldiers like this texture is for often wore their robes over top of their armour. (Please don’t take my mail texture without asking):
Desaturate:
For this particular texture it isn’t a big deal because there isn’t much color in it, but for some it makes a big difference:
Image > Adjustments > Desaturate [Shift + Ctrl + U]
Invert:
Image > Adjustments > Invert [Ctrl +I]
Run the Nvidia Filter:
You’ll need to run the Nvidia filter from the pulldown menu each time you use it. Simply using [Ctrl + F] causes a weird thing to happen.
Repeat the process for the next layer:
~ Remove all drop shadows
~ Do not include any fabric patterns
Fabric patterns aren’t part of the physical shape of the clothing so they should not be included unless they are meant to be raised stitching in which case they should still be very light (not as 3D as a belt). To do this create all your fabric patterns as overlays on your main texture. That way you can also re-use the clothing’s wrinkle patterns as I often do. In this case I made the wrinkle template from Rusichi textures since I’m using a Ruschi model and because they look good.
~ Do include inner shadows.
An inner shadow is usually part of the shape of an object and thusly should be included in the normal map. To do this you will need to create a blank texture below for inner shadowed layer and merge it down before doing the normal process.
Repeat the process for the each layer:
In this case I made the robe trim a separate normal map layer because I want it to look like a separate piece of fabric sewn on.
The final result:
To see some of my normal maps created using this technique in the game, check out this unit preview:
http://www.twcenter.net/forums/showthread.php?t=341275
Originally Posted by Enros
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