I spent another afternoon working on my pie chart project. I'm using PyCairo to render labels over the chart render. The tricky part was finding the position at the center of each pie segment to render the label over. There's no way of retrieving that information from Povray, so I had to do the math myself and calculate the coordinates manually. Fortunately I had a 3D math module that I was intimately familiar with, having written it just last year (its always gratifying to re-use code for a new purpose)!

I won't bore you with the gory details. Suffice to say that I generated a pretty animation so I could confirm that the label position code was working correctly. I'm not going to be generating videos with the finished product, this was just a diversion. The segments and labels don't mean anything, it's all just made up! Enjoy...