BI "Front/Back" vs Cycles "Facing" - Angle of Incidence in Blender Internal In Cycles the Layer Weight node has an output called Facing.

In Blender Internal the Geometry node has an output called Front/Back.



Do these perform the same function and just have different names, or are they doing something different?

Thanks
Do these perform the same function and just have different names, or are they doing something different?


No, they don't. They perform something different:


Facing output from Cycles Layer Weight node gives angle of incidence. You can read about this node and how it compares to the Fresnel node here: Relation between Fresnel IOR and Layerweight blend?

You can make it from scratch in Blender Internal node material like this:


Front/Back output from BI Geometry node is the same as Backfacing output from Cycles Geometry node and gives a binary true/false (1/0) if a face is oriented to the camera with it's normal or not.