Returns the vector that points in the same direction as a reference vector within the visual shader graph.
Translates to [code]faceforward(N, I, Nref)[/code] in the shader language. The function has three vector parameters: [code]N[/code], the vector to orient, [code]I[/code], the incident vector, and [code]Nref[/code], the reference vector. If the dot product of [code]I[/code] and [code]Nref[/code] is smaller than zero the return value is [code]N[/code]. Otherwise [code]-N[/code] is returned.