Not sure if some of you have see the 3D in-door routing application that I did for the ESRI 2009 User Conference. I used Papervision3D for this app, and was a lot of fun to develop. A couple of weeks before the conference, I decided to implement the same app on an iPhone using Obj-C. Being a newbie in the latter, I ramped up quickly on the language (got quickly over my hang ups on bracket, and kinda like the language :-). I started to look at the 3D built-in engine that uses a derivative of OpenGL and thought that I will not have the time to get this up and running. So I started to look for simpler alternatives. I read Keith Peters' most excellent AdvancED ActionScript 3.0 Animation book and used his A* implementation for client side routing application with barriers. check it out here. The next chapter in the book is all about isometric projection. This is exactly what I needed, an isometric view of the CDCC floors and rooms with a small twist, where the user can rotate the view.
So before doing a full Obj-C dive, I prototyped my application in Flex/AS3. The idea was to read a 3D shapefile (thanks Edwin), apply a rotation matrix on the original coordinates and then pass them through Peters isometric utility class. Once debugged and got it up and running (check out the app here, hold and drag the mouse to rotate the view), I ported the code to Obj-C. Check out this post to see some iPhone app snapshots. Like usual, here is the source code of the flex app.