I started a basic demo of steering behaviours using C++/SDL the other day, which are great for getting amazing looking results with very little code. It quickly reminded me of how rusty my trigonometry was though! For example, it took me 10 minutes of scribbling on the back of an envelope before I could prove to myself how to calculate the angle of a vector (hint). Sad. However, I find that proving an answer to yourself is always more satisfying than looking it up, because you come away with not only an answer but an understanding of the process.

My next task is to implement a wandering steering behaviour by randomly displacing a point along the circumference of a circle located in front of the vehicle. It sounds trivial but all the converting to and from angles and vectors and translating from absolute to relative values starts to send me mad after a few hours! This is why I don't tend to bother with 3D graphics...