Creating special shader maps for textures

About Shaders

What is a Shader?

• In the Cube 2 engine (and many other engines), shaders are used to change a texture without actually changing the texture itself. How? A shader will take a 2nd texture, based off of the original, and will apply a special effect based on what kind of shader you use and the texture provided for it.

What kind of shaders are there?

• There are many different kinds of shaders, and you can combine some of them. Here's a basic list of common shaders:
  • Bump/Height: A bumpmap (which may go by other names) is a greyscale image which bumps parts of a texture up or down (raising or lowering parts), based on the color. In a bumpmap, white rises and black lowers, while grey is even. Bumpmaps can be combined with virtually any other shader, and some only work with bumpmaps.
  • Normal/Height/Displace: A normalmap is a red-green-pinkish purple colored image which is more accurate than a bumpmap. It does the same purpose, but on a more accurate and better scale.
  • Decal: A decal is an image which is added to an image after something happens to that texture. In Cube 2: Sauerbraten, decals are used to add bullet holes to textures.
  • Glow: A glowmap allows a texture to glow in the dark.
  • Pulse: Like a glowmap, but the glowing "pulses". It's like a light being turned on and off, back and forth.