In a post last month I showed a video of an optical illusion - a fence that's not really a fence, which can be "assembled" in two different ways. I used this idea to create one of the SketchUp Projects of the Month for May.
I got the idea from a teacher named Charlie Unkeless, who recently sent me his version of the fence, which differed a bit from mine (and I like his better).
Here's the video of Charlie's fence spinning - note the "impossible" placement of the vertical fence posts:
I've placed his model in the 3D Warehouse for everyone to check out. Click the image below to get to the model's download page. Because this model has scenes, don't import it into another model - open this model in its own file. Then click the three scenes tabs across the top to see the fence spin around!
Anyone can design anything in 3D! http://www.3dvinci.net/