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Few Questions...

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I am basically a Game Programmer and have a few questions: 1) What does the term "alpha" mean in texturing? 2) How are shaders different from textures? 3) What is Normal Mapping? How different is it from bump mapping? 4) What is parallax occlussion? 5) What do terms like diffuse map, specular map etc. mean? 6) Why shold texture sizes be in the powers of two? Will I get information on all these common aspects of Game Development from one source specifically? Thanks and looking forward to your replies....

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(1) Alpha is not restricted to the domain of texturing; it applies to color-related domains in general. Alpha is a measure of opacity of a color, typically in the range 0 to 1, or 0 to 255, et cetera. An alpha of 1.0 (or whatever maximum) means the color is fully opaque. Similarly the minimal value indicates the color is fully transparent. Values in between coorrespond to various "degrees of transparency."

(2) Shaders are small programs that execute on the GPU to control certain stages of the graphics pipeline defining, among other things, the way vertices are transformed and the way fragments ("pixels") are colored. This is seperate from textures, which are blobs of data that can be read during a shader to provide information (such as color).

(3) Normal mapping is a type of bump mapping; bump mapping in generally is a way of making a shaded surface appear, well, bumpy. Normal mapping employs a texture map with surface normals encoded into the red/green/blue components of the texture elements (texels). That information is read, per-pixel, and used in the calculation of whatever lighting model is chosen by the programmer.

(4) Another form of bump mapping. Parallax occlussion mapping employs a height map of the surface encoded in a texture, and distorts texture coordinates to give a different appearance of depth and volume to a surface that is, geometrically, flat.

(5) Texture maps that contain properties useful in the calcuation of various lighting models (a diffuse model simulates diffuse, or random, scattering of light, giving a matte color appearance; a specular model simulates mirrorlike "perfect" reflections giving a shinier, plastic or metallic look). These are typically combined in some fashion.

(6) Historically, it was more efficient as it allowed for various assumptions permitting optimizations when graphics hardware was new or nonexistant (and rasterization was CPU-side). Modern cards to not always require power-of-two textures, but may operate on them more efficiently.

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Quote:

Will I get information on all these common aspects of Game Development from one source specifically?

The information is covered in many references and texts. There are a few that purport to be "all in one" sources of such information; many of them are of questionable quality. The stuff is common enough that you will eventually become familiar with it working in the area.

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And what dos a lighting model mean?

The method and calculations used to simulate light interacting with a surface, coloring it and shading it in different ways.

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