OpenGL ES does not have a built in library for curve generation, and while the formulas for creating curves can be readily found there are so many different types and it is always nice to have everything done for you. Core Animation provides a few different types of curves, but there are many more. I found out about some great open source code that performs the necessary calculations for 22 different types of curves. In case you’re wondering why you might need this data — it is extremely useful for animation. Also, this is not only an OpenGL curve library, you can use the functions for different Core Animation curves also.
The library is from Jeff Lamarche, co-author of Beginning iPhone 3 Development and More iPhone 3 Development books you can find out more about the functions, and see some of the examples of the curves at:
More Animation Curves Than You Can Shake A Stick At
Further information on how to use the functions can be found at the above link.
Drawing a 2D Hud on a 3D OpenGL ES scene is a common task when developing games.
To do this without any distortion in OpenGL ES you need to draw your HUD through a matrix different from the projection matrix used for 3D objects.
In the tutorial Jeff takes you through the process of adding a simple HUD to a 3D Scene.
Be sure to check out the iPhone OpenGL ES resources list for more OpenGL ES resources.
source Jeff LaMarche’s Blog
Updating this old list with a few changes. A lot has happened in the Unity 3D community since I created this list: a basic Unity 3D is now free for Mac development, and DiamondTearz blog is no more, but has been changed to another site known as InfiniteUnity3D
Official Unity Resources – This is a wide collection of Unity iPhone resources including tutorials, sample projects, and the like. The Unity 3D people have really done a great job putting all this together. It’s really second to none when you look at the resources available for other iPhone game engines. The place to start is the videos. I think this is a great example of what other engine/game creators should try to put together.
Infinite Unity 3D – This is a terrific resource, the creator who ran the DiamondTearz blog previously has now created this site exclusively for helping Unity 3D users.
UnifyCommunity Wiki – A great wiki that is a tremendous resource for those developing with Unity 3D.
Those are the most helpful resources that I’ve found for dealing with the Unity iPhone game engine, as I said the documentation/examples are extensive on the Unity 3D site so you will want to start with those, but it can be great to find other perspectives.
The engine has also made great strides since their initial iPhone release so if you didn’t like it initially (there were some performance issues that seem to have been alleviated) you will probably want to check into it again as it has really become the market leader for 3D game creation tools on the iPhone. The iPhone version offers a free trial.