From Kyle's article: "... Imagine a game like Pong, except with a rotating triangular ball. This ball needs to have perfect collision detection with the paddles, which means if any part of the triangle intersects with the paddle, there is a collision. You can’t just do simple radial collision detection, nor can you do rectangle collision detection, because the triangle might not actually be colliding for some collisions detected in those cases. However, performing the triangle-to-paddle collision detection can be expensive to do every frame (I know, not that expensive – but imagine 200 balls with 30 players around a big field with balls also colliding with each other, or something like that). So what are you to do? ...".Read on!