passing custom variables into surface shader

Unity Engine
1

Has anyone done it? I’d like to get specular color from a separate texture and pass it into a custom lighting model.
Basically, can we have more float3 channels than Albedo,Normal and Reflection? I’ve run into some trouble,with the compiler failing to allocate the added output.

2

Yes this is possible.

in your script:

void Start(){

    public Color colorBalance = Color.white;

}

void Update(){

    myMaterial.SetColor ("colorBalance", colorBalance);

}

in your shader:

Properties {

    colorBalance ("colorBalance", Color) = (1,1,1,1) 

}

...

float4 colorBalance; //declared outside of structs

...
3

thanks for the comment , you kind of misunderstood my question, but i luckily found a solution anyway, posted a sample in this thread:
http://forum.unity3d.com/threads/62685-Bump-color-spec-shader-not-working-in-Unity3.0