I decided to do a nice and easy tutorial about creating Normal and Specular maps for Blender.

If you don't know what does a Normal map or a Spec map do, then I tell you:

Normal maps

Normal mapping is superior to the technique that we used before, which is Bump Mapping. Superior in the way, that Normal maps store RGB image and direction information instead of grayscale image and intensity information, unlike Bump maps do. This allows us to fake bumpiness on a flat surface, until the camera closes a flat degree with the surface. An other withdraw to Normal mapping is, that we cant paint it in real time, Normal maps need to be generated in a way.

There are a bunch of tools for generating normal maps, NVIDIA tools and other, even free open source ones, but give you one that even works with your browser!

[ SmartNormal ]

Click here for more information about normal mapping in blender.

Specular maps

Specularity is the visual appearance of a specular reflection, a highlight on the surface, which is generated by uneven lighting. Specular maps help rendering engines decide where they should highlight your objects, and which parts should remain dark. With this method, we can spare lots of computing time, since the CPU don't have to calculate all the bumps on the surface, and the outcome is still relatively believable.

Lets see these two in action:

 

Creating a Spec map:

There are two ways to create these, first is to bake them in Blender, the second one is to generate them using GIMP or Photoshop. You can use either GIMP or PS or any other image manipulation application, which uses a Level adjusting tool.

Texturing the plane

1. Unwrap your plane (optional)
2. Add a new material
3. Add a new texture:
Load your colour map/source image and ->
Image/Uv/COL(UVTex)/Flat/Color:1.000

Creating Spec maps

1. Load your source image
2. Desaturate it
3. Adjust the (input) levels to the point, when only the parts where you need some extra lightin (or any at all), are white. The other parts should be dark, or at least a very dark-grey.

Applying Spec maps

1. Add a new image texture to your stack.
2. Use the same mapping options but
Col: 0, Specular - Intensity:1.000/ RGB to intensity / Blend mode : Multiply, Overlay

Creating Normal maps

1. Load your source image
2. Crank up the bias / chose sobel if you like the results better
3. Save the normal map, and then do an other version with blur cranked up around the middle. (Optional)
4. Combine the highly biased one with the blurred one in GIMP or PS, use Hard Light or Overlay for blending mode. (Optional)

Applying Normal maps

1. Add a new image texture to your stack.
2. Mapping is the same + under Image Sampling, tick "Normal map"
3. Col:0 Geometry - Normal: 1.000 or as you like it

I hope that I can help a lot of you with this small amount of information. It really helped me out when I finally found enough info about these two, and they add to my works a lot! And the best thing is that you can use these in real time. The way to do that is: Press N to bring op the toolshelf, scroll down to Display, switch the render from Multi Texture to GLSL and then switch to Textured mode. If you have some lights around and set up well, you will see the results in real time!