DeepEnd(cydia tweak) like 3D background for iOS

I am trying to emulate 3D background in one of the application we are developing.

Check this video on what i am trying to do : http://www.youtube.com/watch?v=429kM-yXGz8

Here is what i am trying to do to emulate this 3D illusion in our application for iPad.

I have a RootView with 3 rounded buttons centered on the screen which animates in circular motion.
On bottom screen i have some banners of size (600*200) which keeps rotating with flip animation.
I also have some graphical text that is part of the background which contains the "Welcome message"

All elements are individual graphics, and hence when the user moves the iPad we only move the background based on the position of iPad using x,y,z coordinates of accelerometer.

the background moves accordingly, however this is not enough to have 3D illusion, so we decided to add some shadows to graphical elements(buttons, banners, text) and move the shadow accordingly with the iPad's position.

However the result is not convincing, and accelerometer is not updating value if user moves iPad to left and right on stand up position facing iPad straight to the head.

I was wondering if anyone have tried to achieve something similar with success? or any resource to help on how to achieve this? i am just confused whether by using only accelerometer will work or should i go with gyroscope?

Solution

Using face detection for simulating a 3D effect already has been done (by me). You can download a complete sample from http://evict.nl/code/face-tracking See the video on that page for a quick demo.