what does "saturate" mean???

void surf (Input IN, inout SurfaceOutput o) {
o.Albedo = tex2D (_MainTex, IN.uv_MainTex).rgb;
o.Normal = UnpackNormal (tex2D (_BumpMap, IN.uv_BumpMap));
half rim = 1.0 - saturate(dot (normalize(IN.viewDir), o.Normal));
o.Emission = _RimColor.rgb * pow (rim, _RimPower);
}

what does it mean?????...where can I find its and other built-in mathmatic operation in Unity mannul??

 

Here you can find a list of CG standard library functions: http://http.developer.nvidia.com/Cg/index_stdlib.html

Saturate is a function that clamps it's input between 0 and 1.

 

It clamps the value so that it is never larger than 1.0 and never smaller than 0.0.

It's not a function Unity created, it's part of the CG shader language.

 

thanks a lot....

 

That's what i need.
Thank you!

 

anyone know how to average two values? i can't find a function that does this!

 

(col1 + col2) * 0.5 ?

Or lerp with 0.5