Parametric & Customizable dSLR Camera Lens Hood Creator

WIP! My 2nd OpenSCAD file ever! Expect a lot of changes to happen.

This attempts to create a hood for any lens out there. Well, at least one I can get my hands on.

There are three hood types you can choose from.

1. Petal hood. It has cut outs made around the barrel of the hood.
2. Barrel hood. No cutouts.
3. Cine / cheapo matte box. It will project out a box beyond the confines of the barrel.

There are various lens manufacturer bayonets listed. I'll be adding more as time goes, but the Canon one works pretty well so it's time to publish.
0) Friction fit. The universal one.

1. Canon. This one works pretty well. At least it did with my 24-70mm F2.8L, 17-40mm F4L, and 17-85mm IS USM.
2. Sigma. I'm still messing with this one.
3. Nikon. TBD. I haven't measured and tested it with the lens I have.

The formula used for Angle Of View (AOV) is
Unfortunately, lenses and optics are filled with mystical unicorns and are incomprehensible to me.

So, I added in a way to move the AOV generated features in the Fudge Factor tab.
The one that "should" get the most use is the Bayonet_Hood_Distance. On my Canon 17-40mm F4, -41.5 looked really promising. On my Sigma 70-200mm F2.8, it was more like -150.
The Angle_of_view_Fudge value is there for you to play with. However, a 0 value is probably just fine as the problem isn't so much the shape of the feature, but how big the feature is. Not sure that makes sense... Again, voodoo.