Outcome

Ah, optical illusions. Since middle school, this subject has been a favorite of mine. I had always considered optical illusions an amazing synthesis of science and art, I have never found a more impressive artist than M.C. Escher (Can you imagine that his works are lithographs?), and I have yet to tire of the subject! I could say much about the many optical illusions people may be familiar with, but I will focus on those that use parallel perspectives to create impossibilities. I cannot explicate its mechanisms fully, but I hope to demonstrate its gist through examples.

Perceptual Illusion

Parallel projection is a typically used graphical projection used typically for depicting schematics and other images of a mechanical nature. In a parallel projection, there is no adjustment for depth, so all objects appear to have the same relative size and distance. In technical design, this is convenient, since all units are accurate and there is no adjustment for scale required. For the layman, as well, this method of projection seems to make sense. Even if it lacks true depth, people can cognate the illusion of depth easily.

The mechanics of parallel projections are inconsistent, however. Two figures may appear to have the same size while they might be fifty units apart in distance, and thus, people become flummoxed when they want to interpret depth when in a projection that strips itself of depth. The lack of depth in parallel projections makes it not only marvelous for technical drawings but also creative drawings. If people cannot tell how close two figures are, then the artist can purport that it can be interpreted in both locations in space. Video games, in particular, exploit this property, and, most famously, M.C. Escher employed parallel perspective extensively in his artwork:

Mass Media

The problem with designing this illusion in real life is that it inherently relies on a false perception of perspective. Neither the human eye nor cameras can properly parallelize their natural perspective projections, so the closest this illusion can be seen in real life is when people use it alongside a forced perspective—in other words, a change in scale that ‘flattens’ a figure. A classical example of the use of forced perspective is how the ancient Greeks built their temples; to make temples look orthogonal and consistent from a distance, they built their temples such that their pillars were inclined and the proportions were somewhat ‘inverted’ from how the eye distorts them, so the temples would look ‘corrected’ from a distance.

A more modern example of this illusion being used is the Trompe-l'œil, which uses forced perspective to give depth to a flat surface. Chalk art, in particular, stands out, as it can be considered both street art and an installation piece.

While the above examples are intriguing, where parallel perspective becomes really interesting is when it is not only used but exploited.

Media Art

Before the early 2000s, many games could not efficiently render true 3-D perspectives, so developers compensated by using parallel perspectives, which emulated 3-D without rendering needed. In particular, isometric projections were popular.

A game that stood out to me for its use of isometric projection is Diablo II. In the game’s lore, there is an extradimensional location called the Arcane Sanctuary, and to demonstrate just how bizarre this place was, the designers implemented subtle optical illusions while procedurally generating the level.

In the movie Inception, the concept of paradoxes is weaponized by the character Arthur. Upon being chased down a stairwell in a dream, the stairs become a Penrose Staircase and wrap around, allowing Arthur to get behind his pursuer and push him down the newly-formed gap.

Then we come to Echochrome, the game where the entire basis of its gameplay is this illusion. If the player rotates the camera in a level such that some perspectives match up, the illusion becomes reality. It takes M.C. Escher’s designs and turns the optical illusion into an interactive puzzle game. Just for additional artistic value, the player character is an artist’s model.

Reflection

I have been familiar with optical illusions in breadth, mechanics, and execution, so while it may be easy to design something involving optical illusions, making something ingenuous I have not previously considered or seen is challenging.

Well, how about this? All of the examples of parallel projection paradoxes presented seem to be orthogonal in nature. I think that breaking this restriction and would contribute an additional level of trickery. This is challenging, of course, because as evidenced, humans tend to follow lines along orthogonal planes, and decomposing perpendicular lines may cause a loss of illusion, depending on how the image is structured. Alternatively, it might contribute to the illusion further, given how it is harder to follow. Should I exploit this illusion, though, I will really have to be mathematically meticulous and plan my work ahead.

Additional Sources

Aronsson, Andrea. "Gallery." A. Aronssons WeBOLLog. 29 Oct. 2010. Web. 15 Oct. 2015. <http://andreasaronsson.com/impossible-figures/gallery/>.

Blankenbehler, Benjamin. "How Greek Temples Correct Visual Distortion." How Greek Temples Correct Visual Distortion. 14 Jan. 2014. Web. 15 Oct. 2015.

Westerdiep, Arjan. "Drububu's Pixel Art Tutorial." Drububu.com. Web. 15 Oct. 2015.