ShaderNodeDefinitions{
    ShaderNodeDefinition ColorToGrey {      
        Type: Fragment
        Shader GLSL100: Common/MatDefs/ShaderNodes/Basic/colorToGrey.frag
        Documentation{
            Retrives the individual color channels
            @input color the color
            @output greyness or lightness of the color
        }
        Input {
            vec4 color        
        }
        Output {
            float grey
        }
    }
}