As this was going to be my 100th perspective illusion I figured I would have to do something special, more so than usual. I decided to do a homage to the first scientifically published impossible art, a Penrose triangle or tribar. The article that included it was published way back in 1958, by the late L. S. Penrose and his son R. Penrose, two multifaceted people as you can read on their respective Wiki-pages (with reservations because who knows how correct those are).
This is probably the first illusion I have created where I started out directly in CAD with no base model created in 3D first. I had to figure out how to place my perspective points, and the eventual and fairly obvious answer in this case was to use the corners of a like-sided triangle.
The three rectangular bars are placed in 3D space in such a way that the front end of one connects to the back end of another. This way you can travel continuously back into the picture or forward out of the picture by tracing the shape.
I would have loved to just quote the article in question, but I guess that would not sit right with the publisher. While on the subject, I was looking to acquire the original article to make sure I was referencing the correct art, but to get my hands on a digital copy I would at the time have to pay John Wiley & Sons a whopping US$43.75 for only 24 hours of access. In addition the article itself is only three pages, that is almost $15 per page!
As I thought this to be unreasonable I contacted them about it, wondering if there was no cheaper way to gain access, but there was none. Instead I had the extreme luck to find a withdrawn library book containing the original article, specifically the British Journal of Psychology volume 49, 1958, on Amazon UK for £10!
So, here in my hands I have an actual physical copy of the entire book instead of a digital version of just three pages for a quarter of the price, and I have permanent access to it too! I’m blurring out the text on my photo below because the art itself is readily available online (reference) but the text is not.