ok thanx a lot to take time answer to my question but my real question was (it wasnt clear)how can i create a shader. do you create your own specular ramp, diffue ramp... and then connect that to your "premade" material.. i know a lot about bump mapping uv mapping, texture.now i want to learn more about refletivity , specular , diffuse. how you create these attribute for object to give it a metal look. plastic look...

how do you start to make your shader.
finaly whats these attribute make to an objetc.
if you create a specular, difuse or reflectivity ramp for your shader,what are they going to do on your object.
ex: if your reflective ramp color is red what is going to do on your object.

what these attribute are going to do on your object and is there many way you can create it.

diffuse
reflectivity(color)
specular.

i want to know how you create a metal look plastice look ...

if you have a tut about how to create your own shader,can you give it to me please.