This polygon mask was made on a Shopbot CNC router.
THIS INSTRUCTABLE WAS MADE @ TechShop Detroit
Step 1: TAKE FACIAL MEASUREMENTS
TAKE MEASUREMENTS, do some crazy CAD sweeps or make it manually with extrusions. If you want this polygon shape with three planes: I used 2 datum planes an inch apart. Then on the bottom plane I sketched a 6 side shape. On the datum plane above that one, offset the sketch smaller and sweep the two together,do this again for a 3rd plane even smaller and sweep again. Keeping in mind the three inches, leave about in inch for the nose.
leave tabs on two arbitrary locations so that the mask can be supported while cutting.