Archive for October, 2008


As luck would have it, I bought an iPhone two weeks ago. I’m not one of those rabid Apple fans. But once I could get Exchange support directly, I figured having my work meetings and email on such a nice mobile display would be well worth it. I hadn’t even registered for iTunes to download apps (even the free ones require your credit card, apparently) — until Google Earth came out.

My impressions — even at 3G speeds, it’s incredibly impressive. The touch interface is great, though not perfect. It’s probably an issue of sampling the device when framerate is low (Apple should ensure the UI is not bound to app or render rates). I did find that the two fingered motions tended get results that drifted from what I wanted, which I attribute to the size of the screen vs. my hands and not to any math error.

I’m not too surpried about performance. It reminds me of how the original Keyhole app ran on unaccelerated laptops. Without terrain, the number of triangles shouldn’t be the limiter (you only need about 1000 triangles to make a nice sphere, even less by the time you need to see placemarks). Texturing, caching, and download speeds seem like they would have been the biggest challenges.

I imagine the optimization work that Google did to make the app run 4+ instances in a browser was vital to this iPhone work as well. But keep in mind, even the idea of using 500MB of storage is problematic on an iPhone. Fitting the Universal Texture code to run in the small main memory must have required some significant tradeoffs, of which I can only speculate. But the results still look very good.

I’m looking forward to trying it out in the field.


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