The Art of NSLog

Ever wanted to know how to disable debug messages in release mode? How to print out the name of the current function that is being called? The current line in the source code?

All this can be done with the help of NSLog and some macros.

Exporting Objects from Blender into Your iPhone App

As OpenGL ES provides no standard format for importing 3D meshes, you will need external tools to display non-trivial 3D meshes in your app. Blender is a well-known open-source 3D modeling tool (of course you can do almost everything else 3D-related).

Here is a good tutorial which shows you how to export your meshes from blender to a format that can be used in OpenGL ES applications, for instance on the iPhone:

• Blender to iPhone, part 1 (Blender & Python scripting)
  
• Blender to iPhone, part 2 (export from Blender and import to Obj-C)
  
• Blender to iPhone, part 3 (textures and UV mapping)
  

Accessing Views Created in Interface Builder

There is an easy way to access views created with Interface Builder in the view hierarchy.

In Interface Builder, set a value for the "Tag" property of the subview (first pane of the info window) you are interested in.

Then, you can programmatically access the subview of a view with tag value n with the following command:

UIView * subview = [view viewWithTag: n];

This technique is very useful if you want to manipulate views created with Interface Builder at runtime.

iPhone AR Kit

Some nice developers released an iPhone AR Kit. This means that you can process camera images in real time and to some neat stuff with them.

Original Article

iphonear.org

Google Code Project (iphonearkit)

RouteMe: Free Slippy Map

We are currently testing an accelerometer-driven dynamic zooming map application and use RoutMe to display our map.

If you need a free slippy map view for your application, that is independent of Apple's MapKit then RouteMe is the right project for you: http://code.google.com/p/route-me/ .

RouteMe offers a great deal of flexibility as it can display maptiles from different sources such as OpenStreetMap, Google, Microsoft or your own custom tiles.

RouteMe still has some bugs and is in need of contributors, so if you are interested please contact the RouteMe project team.

iPhone 3GS Impressions and Speed

We finally got our first iPhone 3GS yesterday. It at appears to have a much higher performans than the old iPhone 3G. Our autozooming map application, which uses a 10GB tileset consisting of about 3 million individual map tiles, runs almost as smooth as on the iPhone simulator. On the iPhone 3G, on the other hand, we had severe performance problems. On a side note, our iPhone 3GS doesn't seem to have the temperatur problems reported on some websites.

The high performance has two consequences for the iPhone Developer community. The good one is that the iPhone platform is ready for really computational-intensive applications, such as AR using live camera image processing. On the other hand, the iPhone 3GS opens up a compatibility rift between the new devices and the previous generations, forcing developers to decide which devices to support in their applications.

For new iPhone buyers, I would definitely recommend the iPhone 3GS as it seems to run better with the new 3.0 firmware than older devices, due to its increased processing power.

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