Brandy Glass

This is a little throwback to my student days. One of the projects we were assigned for our 4th-year Graphics and Dynamic Control course (with Dr. Mike Scott) was to animate a wireframe 3D model of "something". My friend and project-partner Brian Boyle and I decided to do a brandy glass, much like the one shown here. It is a project I really enjoyed doing at the time (Brian and I went all-out do do a good job on this one), which is why I wanted to recreate it here.

The animation you see here is written in HTML5/Javascript, while the original was written in C. The project is considerably easier to do now than it was the first time around in a number of respects:

There is a little bit about the maths involved in doing the 3D transformations at Also worth a look is the brilliant 3Blue1Brown video series on Linear Algebra that kicks off at

One aspect of the original project that I haven't (yet) reproduced here was that the motion of the glass was "realistic", in response to forces applied to it. This involved using the Runge-Kutta method for calculating the motion of the object. The one here just spins at fixed rates around all three axes.

Ofcourse, this isn't at all how you would do something like this now. All of the heavy lifting here is done by the main CPU. Any modern computer (or phone, for that matter) has hardware-accelerated graphics that can do the computations and rendering vastly quicker and more efficiently than is possible using the general-purpose CPU. The right way to do this here would be to use WebGL which is a Javascript API to OpenGL. That's an exercise for a later date. When I do it, I'll probably use three.js to hide some of the complexity of WebGL.