Radiohead’s latest music video was shot without cameras. Instead, they used a combination of reflected light and lasers to generate clouds of points in 3D. Google was nice enough to provide the rest of the world with some of the 3D point cloud data collected for that music video. A big piece of that data is about 2100 frames of lead singer Thom Yorke’s head. A frame of the original data (when output via Processing) looks like this:
If you look closely, you’ll notice that the point cloud is really noisy around the edges. A simple high-pass filter later and that same frame looks like this:
That’s a little more manageable. I figured, why stop at point when you can have 3D surfaces? One of the more straightforward ways to make a 3D surface out of a bunch of points is to stick a bunch of triangles in between the points, creating what’s called a Delaunay triangulation. This is a really compute-intensive calculation and I don’t exactly have a supercomputer on hand, so I did a lot of fudging and approximation. Even with all that fudging, each of these frames took as much as 5 minutes to render. This process has been running for most of last week while I’ve been at work. That same frame above looks like this when Delaunay-triangulated:
Notice that it’s a little noisy, which is mainly due to some approximation on my part as well as some leftover noise in the point cloud. The video below shows what happens when you sequence all 2100 frames together. Enjoy!
Posted: July 12th, 2008 | Author:Alex | Filed under:Computers, Ranting | Comments Off
So anyone who has an iPhone or iPod Touch will be pretty aware that Apple’s update servers basically fell over in response to all the demand today due to the new iPhone firmware. Recently, Firefox’s update servers suffered exactly the same problem. Now I’m sure that these guys have a really expensive load balancer in front of their update server cluster, but why in the world are so many major companies still having all their users go to a single place for updates?
If I want to download an update from Software Update today on my home computers, I have to do it three times - once for my Mac Mini (file server/backup server/media center), once for my laptop and once for my tower. The actual update binary is, in most cases, identical. If I wanted to only download the update once, I’d have to find where Software Update keeps the update’s installer file, copy it to the other machines and run it there. In some cases I have to download tens or hundreds of megabytes of file that could easily be transferred over my home network, saving both my time and the update provider’s money.
The thing that’s the most irritating about this is that it’s a completely solved problem. Blizzard, for example, distributes updates to World of Warcraft over Bittorrent. My roommate just started playing WoW again and had to install a patch (~2 GB) on two of his computers. He downloaded and installed the patch on the first computer, which took about an hour and a half. The download-and-install process for the second computer took all of about five minutes because the computer automatically recognized that a source for the update existed on its local network and downloaded the file peer-to-peer from the other machine.
Imagine if everyone interested in downloading the iPhone patch could download it not only from Apple but from each other. After the first few hundred downloads (which would have to pull directly from Apple) most of the remaining transfer would be peer-to-peer. If iTunes needs to authenticate the phone with Apple before installing, that’s fine; the load on the servers from authorization would be far lower and of a much shorter duration than the load from patch downloading. Security, of course, is an issue with Bittorrent-esque downloads, but there are relatively straightforward ways to deal with that.
I’m just saying it’s about time that someone did something about this, because it’s getting a little ridiculous.
So anyone who has an iPhone or iPod Touch will be pretty aware that Apple’s update servers basically