Can Unity iPhone use the UIImagePickerController::cameraOverlayView(iPhone 3.1 API)?

I want to develop the Argumented Reality iPhoneApp with Unity iPhone. Can Unity iPhone use the UIImagePickerController::cameraOverlayView(iPhone 3.1 API)?

Yes, you can. Opening the camera isn't too hard; just create and present a UINavigation controller, create and present a UIImagePicker, and don't forget to have a delegate object ready to catch selected and cancelled messages. The bigger problem is turning the Unity scene into an overlay that you can stick on top of the camera; you'd have to get the bits of the OpenGL display, turn some background color into alpha bits, put it into a UIImage, and put that into a UIImageView that you could add to the cameraOverlayView. It seemed simpler to go the other way -- pulling bits from the camera preview and sticking them into a bitmap in Unity. However, Apple has been rejecting apps that did that.

I'm no expert here, but I believe you can call that API yourself, using Unity iPhone's, Cocoa bridge. it basically allows you to write ObjectiveC code against the iPhone SDK, if you find that you want to call a iPhone SDK function that Unity doesn't expose natively.

As Lucus mentioned, you will need the Pro version and you'll have to use the scripting bridge.

It is doable using the SystemPrefs trick to communicate with Obj-C but there is no way in hell you are going to get anything close to usable performance doing it even on a 3GS.