Computes the facing ratio of the geometry : a simple dot product between the camera vector and the surface normal. @parameters
use: Traditionnaly, the facing ratio is computed using the surface normal and the camera vector : This is the Camera mode. It can also be useful to the surface normal with an arbitrary direction, for example to create a dust mask on up-facing parts of a model : This is the Direction mode.
direction: Only active in Direction mode. Defines an direction of your choice
coordSys: By default, the direction is in current space. Possible coordinate systems include world, object, or an user defined coordinate system.
faceForward: 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.
clamp: Clamps the result between 0 and 1.
invert: Inverts the facing ratio : black becomes white and vice-versa.
gamma: A simple gamma function to shape the facing ratio. A value of 1.0 is neutral
bumpNormal: If the surface is bump-mapped, input the bump normal here. If not connected, the node will use ths shading normal.