shader

Hi guys,

i am new to shader. Could unity create own bump maps and colored speculars? If i use bump maps need i several light sources? Will performace decrease if i use layered shaders?

Yes.

Bumpmapped shader most likely would be a pixel-lit one (as lighting calculations will be done at pixel level). So if you do a proper pixel-lit shader, it will “just support” any number of light sources (as well as all types of lights).

What do you mean by “layered shaders”? Multipass? Yes, more passes = lower performance. This is just the way things work; as more passes = more work for the graphics card to do.