I just got back from a very interesting week of listening to scientists from around the world presenting papers on all things 3D. I was also a presenter at the poster session a few days ago (January 25, 2011) where I talked about human perceptions as it relates to content creation for 3D.
Essentially, my theory is that 3D can’t be described in a single formula which, if followed, assures “perfect” 3D. Yet this is the approach many 3D content producers are taking and one that many scientists are keen to say that they provide.
I listened and watched as scientists talked about formulas for 3D vision comfort (VC) as if VC was an obtainable and definable numerical value. There were formulas for parallax, screen size, viewing distance, lens to lens spacing for cameras, angular distortions, etc. and many claims with regards to things that define “quality 3D”.
Now, I totally agree that there are many things that can be measured with regards to the human eyes. And that information can be useful in terms of what is the “normal” use for the eyes. And there is plenty of evidence that convergence and accommodation are key components for people being able to “see” 3D. But for me, the real meat and potatoes has little to do with these outward measurements. We don’t see with our eyes anymore than we hear with our ears or smell with our nose or taste with our mouth or touch with our skin. Those things only help to facilitate the experience. The thing at work that actually DOES see and hear, smell, taste and touch is our brain. Our brain takes in the information and processes it and provides the human perception experience.
The more clues we provide to the brain with regards to 3D, the better the experience. And especially when there are conflicting clues – we need to help offset that by countering with supporting cues.
I think it is commonsense that if you present a 3D image with convergence decoupled with accommodation and you add in camera shake (perceived motion visually, not matched to the inner ear), and you ask the eyes to diverge in a way that would never happen with regular viewing, and you throw in a dose of 2D to 3D conversion errors where the left eye has differences with the right eye and spice it up with a touch of vertical misalignment… There you have a recipe for a formula that probably equals VNC (vision NO comfort). AKA “headache inducer with a side order of vomiting”.
I submit that even with all of those poorly advised components, that a person so motivated to engage in learning to suppress the perception conflicts mentioned above and learn to overcome and train the muscles to accommodate “unnatural” viewing conditions… that person could watch the content and get something very positive out of it because the content is being processed and understood and given context and meaning by the brain which is incredibly adaptable to new experience.
Think about it, our early ancestors didn’t have books that required focus and convergence for an object held 18″ from our face (sometimes even closer). Think about the resolving power and eye alignnment required to read the tiny text of a web page on an iPhone. Think about the increase in ambient noise we live with every day that would be deafening to our ancestors. Similarly, I suspect that certain foods that we eat in today’s world would have caused our ancestors to vomit violently. One of my favorite examples is the scene from the movie “Back to the Future” where Michael J. Fox’s character puts earphones on his 1950’s Dad and blasts distorted electric guitar sounds that struck terror and fear into the 1950’s character.
Technology is evolving rapidly, yet evolution takes hundreds and thousands of years. Fortunately, our brain has the ability to adapt. The key is understanding that adaptability and where it is “good” and where it might be “bad”.
Lets say you want to be a weight lifter. Well, I wouldn’t suggest signing up for an extended stay at the orbiting space station where astronauts are “training” their bones to lose density and their muscles to atrophy. Yes, they are training their bones and muscles because they are exposing their bones and muscles to zero gravity. Well, if you expose yourself to stereoscopic material that has multiple perception conflicts, you are training your brain to ignore and/or accept that reality. If that is in preparation for the need to do that, then that might be a good thing. If not, then perhaps not a very good thing – especially if reversing the brain’s adaptation is difficult.
All of this has got me thinking a great deal about studying the brain in greater detail to learn more about how my imagery, and 3D in general, triggers brain activity and response and perception.