All in max yeah.
Difficult?....
Implementing a Shader system wasn't too hard, the actual shader language is another matter, GL Shader Language (GLSL) specs & manual are here: http://www.opengl.org/documentation/oglsl.html
You can use programs like www.typhoonlabs.com Shader Designer or ATIs RenderMonkey http://www.ati.com/developer/rendermonkey/index.html to aid in designing Shaders (both currently free programs!)
Difficult?....
Implementing a Shader system wasn't too hard, the actual shader language is another matter, GL Shader Language (GLSL) specs & manual are here: http://www.opengl.org/documentation/oglsl.html
You can use programs like www.typhoonlabs.com Shader Designer or ATIs RenderMonkey http://www.ati.com/developer/rendermonkey/index.html to aid in designing Shaders (both currently free programs!)