Public Domain Involute Parameterized Gears: Optimized for Speed

This is remix of @3dexplorer's excellent Involute Parameterized Gears. This code is optimized for speed (generating gears is faster).

The original code creates an implicit union of several 3D linear_extrude's. It's faster to draw several polygons in 2D, then apply one linear_extrude at the end.