In short I've made a little 'game' (which is a stretch of the term, I guess it's more of a demo that one can participate in) in which you play a blue ball which can shoot down the multi-coloured balls coming towards you. As indicted above it uses basic Opengl ES, also touch screen capabilities and the iPhone accelerometer. So in short a good little project to learn the ins and outs of the iPhone.
One area of 3D programming I hadn't delved into before was collision detection (my old direct-x demo simply 'flew' around a track), I managed to find some code for it in java (it was originally written for a sony-ericsson I believe) - translated it over to objective-c (note the little pinkish cloud on the second screen shot ~ collision detection in action) and it did the trick. The main thing to remember is collision detection can be very computationally expensive if done wrong (which is even more true on a mobile platform) hence the way to do with a low computational penalty it to surround a 3d model/object with a invisible cube. In this way the collision mathematics is only based on intersections of simple cubes rather than the complex 3d model they encapsulate.
One site I can recommend is; http://nehe.gamedev.net/ it will give you a good starting point on opengl.
Well thats all for now... now back to my home DYI project from hell (another worthy blog post which I may post about later).
