You can also do it in the 3D environment sir 90% of my CAM work is on the 3D environment, I only use a CAM software just for dictation on which one to cut first and so on and so forth, honestly I really dont know what is a G numbers? but I can use a CNC with precision and accuracy and staright to the point CAM work. so I guess this is mathermatics again, different solution but same answer.