This is a demonstration of a very simple 3D rendering system. It uses simple formulas to project 3D coordinates to a 2D drawing context in HTML5/Canvas. The idea is that this is very simple, and requires none of the overhead of a powerful 3D rendering engine such as WebGL/three.js. The purpose of this is to enable creation of simple, interactive 3D diagrams. (This app lacks interactivity, but it is animated.)
The coord axes are shown, with the x-axis in red, the y-axis in green, and the z-axis in blue. (Coords are oriented as typical in mathematics, with the z-axis vertical.)
In this rendering, the isosahedron is not rotating, but instead, the camera orbits the z-axis, always looking towards the origin (it is a bit above the xy-plane as it orbits). The idea is that a 3D diagram would easily be viewed from various locations.