We can easily find the c# or unity3d code document, but Unity3d doesn’t give the shaders’ code document,and How can I found about "TexGen " “EyeLinear” “combine texture” ,what these words means?
How these words effect the material?
unity shaders are generally written in CG/HLSL. NVidia’s version, not to be confused with Microsoft’s HLSL, though they are rather similar. Asking Google about “CG shaders” would be a good place to start; nvidia also has some official tutorials as well. GLSL (OpenGL’s shader language) is also an option, but only on certain platforms; CG/HLSL is recommended.