Unexpected . expecting ) error for dot product

Unity Engine
1

Hello

I have an error with my shader, but am unsure how to fix it.

I am trying to get the angle between the camera direction, and the normal direction. And if the angle is above a certain amount make the albedo red, else use the texture.

But i get this error on the creation of the dot product line:

Unexpected token ‘.’. Expected: ‘(’

Here is the surface function, input struct and my defined variables:

    struct Input {
        float2 uv_MainTex;
        float2 uv_BumpMap;
        float3 viewDirection;
    };
 
    // variables
    sampler2D MainTex;
    sampler2D BumpMap;

    void surf(Input IN, inout SurfaceOutput output){
        // error is on this line for some reason
        float dotProduct = dot( output.Normal.xyz, Input.viewDirection.xyz );

        float normalLength = length( output.Normal );
        float viewLength = length( Input.viewDirection );
        float angle = dotProduct / ( normalLength * viewLength );

        if(angle > 20){
            output.Albedo = (1,0,0,0);
        }
        else {
            output.Albedo = tex2D(MainTex, Input.uv_MainTex).rgb;
        }
        output.Normal = UnpackNormal( tex2D (BumpMap, Input.uv_BumpMap));
    }

I don’t understand what is wrong with my syntax, can any one help explain my mistake?

2

Everywhere you have “Input” in the surf function replace with “IN”.

3

Ah of course, damn VS intellisense or lack of is so annoying. For some reason it highlighted IN blue as if it was a data type.