Friday, June 11, 2010 7:26:13 PM
For anyone who still has doubts, check the video at the bottom of this page from the company that made this. You can see the building from different angles and see how it looks distorted when not viewed straight-on/from the intended viewpoint, like those sidewalk drawings others have mentioned. Yup, as insane as it looks, it's real.
Friday, June 11, 2010 1:35:02 PM
Other key things to point out is that, because the building was mapped out and scanned before the program was created. The program itself knows when the surface that a particular image is to be projected onto is farther away than another area. For example, the pillars. When the projectors go to move an image from, say, the middle door to one of the pillars, which is closer, it actually dynamically enlarges the projected image so that the effect of distance change is negated.
Another interesting thing to keep in mind in this is that "ambient effects" such as the glare from the laser-like effects in the video, are also projected images, just like adding lens flare to a photo. Everything you see on the building other than the dark areas, is projected from the camera, even the things that seem like just natural effects. You have to remember that the fact the building is completely dark only helps, rather than hinders.