Computes the facing ratio of the geometry: a simple dot product between the camera vector and the surface normal.
The facing ratio can be negative if the normal is pointing away from the camera. This will flip the normal to always give a positive result.
Inverts the facing ratio: black becomes white and vice-versa.
A simple gamma function to shape the facing ratio. A value of 1.0 is neutral
If the surface is bump-mapped, input the bump normal here. If not connected, the node will use this shading normal.
The single-component (float) value produced by the facing ratio computation.