.CGFX File Extension
What is a CGFX file?
File created in the CgFX format, a shader format used by Cg (a graphics programming language) for defining the appearance, or effects, of 3D objects; stores source code in a plain text format; referenced by various games and other programs that use NVIDIA's CgFX technology.
NOTE: Cg is used specifically for rendering 3D content on GPUs. Cg stands for "C for graphics," since Cg is based off of the popular C programming language.