Developing a talking app on iPhone/iPad

I want to develop a talking app for the iPhone and iPad. My question is regarding Animations only. I have an excellent 3D graphics designer who will do his part. Being a programmer, what would I need to be aware of? What should I ask the designer to provide 开发者_JAVA百科and in what formats? Which one to use Core Animation / Cocos 2d for development of 3d character?

I suggest that you look into OpenGL-ES if you are going to do 3D animation on iPhone/iPad.

Here is the Programming Guide for OpenGL ES on iOS devices.