Generates the shapes and then serializes them to a JSON file with a list of vertices (positions) and a list of triangle faces (cells) that index into the list of vertices. Suitable for input into Three.js's BufferGeometry or regl.

Icosahedrons can be generated significantly faster than Three.js's version in JavaScript (which I pretty much copied into Rust).

Trunacated icosahedrons (I call them hexspheres) are a bit slower to generate since they are made by generating a icosahedron and then subdividing it into hexagon and pentagon faces.

When rendering hexspheres of detail level 5 and higher and icosahedrons of detail level of 7 and higher in WebGL, make sure to enable the OES_element_index_uint extension since the number of vertices might overflow the normal int index.