I converted some of my TekCAD 3D math legacy into Ruby and released a few classes as the eymiha_math3-0.1.0 gem on RubyForge as part of my *chunks of ruby infrastructure* project. Included are: * Point3 - a cartesian 3D point, with lots of computational methods * Point3c - a cylindical 3D point * Point3s - a spherical 3D point * Envelope3 - an envelope useful for generating 3D extents * Quaternion - a quaternion, math with one real and three imaginary dimensions This code has served me well over the last decade in its C, C++, C# and Java incarnations. It's nice to have been able to rationalize it a bit in Ruby. Take a look at [eymiha_math3 on rubygems.org](https://rubygems.org/gems/eymiha_math3){:target="rubygems"}