Customizable Lens Hood

My lenses didn't come with lens hoods, so I had to make my own. The result: A fully customizable lens hood generator. This can make petal-style or barrel-style lens hoods, reversible or not, two or three (or more) flanges, with various adjustments. Too many details for me to explain tonight, but the SCAD file is fairly well commented.

Warning: It can take many tries to get this right, especially the bayonet mount. For reasons unknown, Canon at least does not standardize its bayonets. Do not try to customize it online, that way lies madness.

Update: The SCAD file now has defaults that don't take forever to render. Change `fn` before you print for smoother walls, and consider changing `mink` for rounded edges.

The STL files are for the following Canon EF-S lenses, but there's nothing Canon-specific in the SCAD file:

Canon EF-S 60mm f/2.8 USM Macro (yes, the field of view is that narrow!)
Canon EF-S 55-250mm f/4-5.6 IS
Canon EF-S 18-55mm f/4-5.6 IS STM

For extra fun, pau