Wow, thinking in 3D is hard. Remember how I was exited about how some simple trigonometry allowed me to easily move objects to arbitrary angles in the plane? Well, doing the same thing in a 3D space was surprisingly difficult. Not that it’s inherently so complicated – just three simple trigonometric formulas, just like the two in the 2D plane. The problem? good luck figuring them out on your own. In 2D I just drew everything on a piece of paper. In 3D? I’ll have to wait for some hologram 3D paper to be invented.

This was an easy case, because I could pretty easily get an answer from Google (here‘s a great page from an American math professor), but the problem is when you have more specific 3D needs, that aren’t likely to have solutions scattered all over the Internet. Right now I need to find out if a line intersects a flat ellipse in 3D space, and not only is it complicated mathematically, but doing it in a programming language makes it much worse. I really hope I’ll have some insight tomorrow.

Computer graphics – you’re a fun, but difficult hobby.

There’s nothing like a good 4-hour bug to kill your programming mood. Especially when combined with buying an awesome new (old) game to procrastinate with. Anyway, a warning for all you future game programmers out there – If you’re going to write any geometry-heavy code (and games often have that), make sure you know what atan2 is and why the ordinary arctangent function is not good for finding the direction of a line.

On the plus side, I almost have a complete collision detection / handling mechanism, which is a very important step (on the minus side, I don’t like the sound of that “almost”).