Anamorphic Illusions in Video Games

By Ian Alejandro Hunter for Cognitive Science C126, Perception

Introduction

When I am asked what some of my favorite hobbies or specific interests are, I will always tell those interested about my unyielding passion for video games. Video games have been a core and consistent interest that extends past casually playing video games to studying them and working towards an eventual career in the game development industry. As I grew older and began to legitimize video games as a viable career option, my outlook shifted to now observing and exploring video games on a deeper and more educational level. Ever since, I have been enthralled by the complexity that goes into the development of most video games, but from all of the various games and genres that I have taken a deeper look into, never has one genre captivated me more than isometric video games.

For those that are unfamiliar with specific video game genres, an isometric video game is one where the player’s viewpoint is shifted and angled in order to reveal areas of the game that would not be normally seen in a typical top-down or side view camera orientation which in turn, allows for a two-dimensional world to appear as if it is three-dimensional. Herein lies one of the most unique visual illusions in video games and will be the focus of this observation paper. What players see when they dive into games such as Pillars of Eternity, Diablo 3, Grim Dawn, and Sid Meier’s Civilization is a vast series of 3-D worlds to explore, but unbeknownst to them, their eyes and visual system are falling victim to an elaborate optical illusion.

Screen capture taken from Pillars of Eternity, developed by Obsidian Entertainment. The image shows these anamorphic illusions in play, the background looks 3-dimensional but is just a 2-dimensional image stretched.

The designers behind these games have taken the beautiful foregrounds and backgrounds in their worlds and have presented them as 3-D spaces, when in actuality, they are simple 2-D images that have been stretched and distorted in such a way that when the camera is fixed at the right angles (x, y, and z), the world appears vibrant and three-dimensional. In the study of perception, this phenomenon is categorized as an anamorphic illusion, or an image that requires a viewing from a certain angle in order to perceive the image in its undistorted entirety. When executed correctly, it can be virtually impossible for players to discern that the background is a 2-D image, which expertly aides in their overall immersion with the worlds and stories that these games present. It’s a unique observation that serves to legitimize video games as a complex art form with various techniques that help take each new game to new heights.

Developer Acknowledgement

When looking to verify this observation, the one true verification comes in the form of knowledgeable developers showcasing the reality behind this illusion. Pillars of Eternity is a fantasy role-playing game that expertly employs this illusion and is also one of the few games in this genre wherein the developers showcase the development cycle in-depth. In a series of developer updates from Obsidian Studios, the creators of Pillars of Eternity, they have given their players a deep dive into the making of the game. In one particular update entitled, “Project Eternity Update #49: Water, Trees, Day/Night, Lighting... All That Jazz,” a lead developer explores the progress of in-game environment rendering and reveals the full render of an environment running in real-time within the game engine known as Unity. This showcase simultaneously reveals and verifies the anamorphic illusion presented in not just Pillars of Eternity, but most isometric video games released or in development currently.

While this illusion may seem straightforward in its verification, the interpretation of anamorphic illusions in these isometric video games is a bit more complex. Looking to the visual cortex of the human brain, we see a complicated and diverse system that bends to the will of this unique illusion. I feel that I cannot simply say that this illusion occurs because that is how the developers designed the game, because that logic doesn’t serve to explain anything. Rather, I believe that this illusion occurs due to our visual cortex being purposely fed information in one light, and then said information is interpreted in our prefrontal cortex in a different light. I believe that through a complex process of visual feedback moving through multiple stages in our mind, this optical illusion gains the ability to succeed and be a fully-processed and normal image. In an article from Neuroscience News.com entitled, “Explaining the Mechanism Behind Optical Illusions,” when discussing a study from Carnegie Mellon neuroscientists, the author details the results of the experiment and states, in response to neurons in mice being halted at certain points of primary and secondary feedback:

Twenty percent of the neuronal activity in the visual cortex was the result of feedback, a concept Kuhlman calls reciprocal connectivity. This indicates that some of the information coming from the visual cortex is not a direct response to a visual stimuli, but is a response to how the stimuli was perceived by higher cortical areas. (Neuroscience News)

From this, we can possibly interpret that these anamorphic illusions are the result of images being perceived in a different manner in what the article describes as, “…higher cortical areas.”

Screen capture taken in-game from StarCraft 2, developed by Blizzard Entertainment.

Analysis and Understanding

One of the most significant topics that we have studied in this class as it pertains to this unique observation, is depth perception and more specifically, scene depth. Professor Whitney went into detail on this topic in Lecture 6B, and what was presented in that lecture fully encapsulates this idea of anamorphic illusions in isometric games. The whole point of this illusion is to present a false sense of depth; to present a 2-D image as if it were 3-D. I have interpreted Professor Whitney’s presentation on pictorial cues as an outline for legitimizing anamorphic illusions, and whether or not they are capable of tricking the mind. Each aspect: occlusion, linear perspective, known size, gradients, height in field, atmospheric perspective, and shadows, all lend a hand in designing these intricate illusions, and each one works in it’s own way within our visual system’s perception of these illusions in order to create a full “3-D” render of these 2-D images.

The follow-up for this observation is actually one of the most unique aspects of the full interpretation of this illusion as it implores physical and live interaction with these isometric games. As a simple test, I would present to a group of participants a few different gameplay demos from a variety of isometric games, anything from Pillars of Eternity to StarCraft, and see if they are able to discern whether or not the background is a full 3-D render or a simple 2-D image. But what is important to note here is that I would ask them to play through one demo from multiple isometric games. From this we can not only explore whether or not a game is able to utilize anamorphic illusions correctly, but we can also cross-reference the different game interactions in order to explore if one game is actually able to create a “better” anamorphic illusion. This experiment would open up several doors for both the exploration of game design and the exploration of how different factors could affect our visual system. I would like to know if different sceneries allow for different interpretations of this illusion. Would a scenery that is more organic, that is containing trees, rivers, and wooden houses, as found in games such as Pillars of Eternity, fare better than more fictional backdrops that depict alien landscapes and space stations, as found in games such as StarCraft?

Conclusion

From this observation, I have had the opportunity to explore how anamorphic illusions in isometric video games allow for the mind to perceive 2-D images as 3-D spaces and further explore the implications that result from such an insight. I feel that overall, this illusion serves to showcase how various feedback systems within the visual cortex and prefrontal cortex work in different ways, therefore resulting in images being perceived in a different light in its journey from the retina to perception within our mind. I know that from observations such as this, our knowledge of perception can expand to various art forms and potentially give new insight into this complex and interesting facet of Cognitive Science and Psychology.

This blog post was adapted from a full-length essay written for Cognitive Science C126: Perception, taken at the University of California, Berkeley. The full paper can be found under the "File Share" section of this portfolio. This is Part 3 of 3 in a blog series on the social sciences as depicted in video games.