I am a very beginner in Objective-C and iOS programming. I spent a month to find out how to show a 3D model using OpenGL ES (version 1.1) on top of the live camera preview by using AvFoundation. I am doing a kind of augmented reality application on iPad. I process the input frames and show 3D object overlay with the camera preview in realtime. These was fine because there are so many site and tutorial about these things (Thanks to this website as well).
Now, I want to make a screen capture of the whole screen (the model with camera preview as the background) as the image and show in the next screen. I found a really good demonstration here, http://cocoacoderblog.com/2011/03/30/screenshots-a-legal-way-to-get-screenshots/. He did everything I want to do. But, as I said before, I am so beginner and don't understand the whole project without explanation in details. So, I'm stuck for a while because I don't know how to implement this.
Does anybody know any of good tutorial or any kind of source in this topic or any suggestion that I should learn more in order to do this screen capture? This will help me a lot to moving on.
Thank you in advance.