I've always been a bit indecisive about posting videos of when I create an impossible figure in perspective. They aren't technically complex to make, it's more about the design and perspective construction, straining the brain.
My worry is of course that someone might take after my working method, but I guess my worries are unfounded as this kind of art, if I can call it that, is fairly niché. Even the classical impossible tribar was drawn in perspective, so it's not like it's a new phenomenon.
Creating these figures makes me feel a bit unique as most impossible figures that are published are created in oblique or orthogonal projection. I still draw that kind of figures, but what challenges and motivates me is to then render them in a perspective view. In addition I strive for perfect correctness, no bent lines or untrue perspective to cheat your way to a complete structure, that's the perfectionist in me at work.
Why I still make few colored simple structured figures is because then they are possible to validate. The lines are perfectly straight, not a bumpy brick wall or other design, so you can with ease trace the lines to their vanishing points. This would have been harder with more artsy graphics.
It was a mess to sift through almost four hours of work and try to find useful parts, but I hope the end result is at least a bit interesting. Most of the work is done in AutoCAD, which doesn't really translate well to video for me with all the zooming and one-pixel lines. Sped up it was around 45 minutes. I've cut that down to about 7½ minutes, which hopefully might be watchable.
Blog post: http://andreasaronsson.com/2008/09/17/impossible-figure-2008-06-03/