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I think you can't. The problem is that we don't actually see 3D, we basically see 2D twice. This gives our senses enough info to reconstruct a 3D mental image,

I think you can't. The problem is that we don't actually see 3D, we basically see 2D twice. This gives our senses enough info to reconstruct a 3D mental image, but the information we gain isn't truly 3D. Actual 3D-sight might include us seeing the inside of objects, what's behind them, etc. We're aided in converting our 2x 2D sight into 3D mental models through the use of color and parallax. In projections on images, it's easy to just use color and get rid of parallax, and still get sort of close. Suppose we tried to make a 3D projection of a 4D world, we don't actually get any significant new tools. We're still going to be limited by having to use parallax and color. This doesn't allow us to add enough information to add that 4D projection into 3D as neatly as the 3D into 2D works. At best you could try to distribute the information somehow. For example by giving information about the third dimension through brightness and the fourth dimension through hue. It certainly wouldn't work nearly as well though.

bunderbunder 8y ago
> The problem is that we don't actually see 3D, we basically see 2D twice. Most of us do. But people who only have sight in one eye have no difficulty perceiving three dimensions. And some fairly large percentage of people with binocular vision are stereoblind, typically without even realizing it. If anything, I'd say it's not that > We're aided in converting our 2x 2D sight into 3D mental models through the use of color and parallax. so much as that we're aided in converting our 2D sight into 3D mental models through the use of stuff like color and parallax through the use of stereopsis.
- lostlogin 8y ago
  As you mention, binocular vision is lacking in a surprising number of people and until recently this was thought to be uncorrectable if not treated while the child was still young. That turned out to be not entirely accurate. Those without binocular vision can have a fairly large range of non-specific symptoms and perception problems. There is an interesting discussion of the change in understanding in this link. http://www.strabismus.org/all_about_strabismus.html http://www.strabismus.org/all_about_strabismus.html
sulam 8y ago
FWIW this is really not true. (The bit about stereo vision being required to see 3D.) When I was in college I was fairly decent on the ping pong table, call it high amateur. I also have very very bad vision - -5 diopters in one eye and -6 in the other. At the time I wore contacts and I was also really really poor. At some point I lost one of my contacts and for six months I was effectively blind in one eye for the purposes of ping pong. It took me about a month, but fairly quickly I was playing at my old level without anything close to stereo vision.
- dsnuh 8y ago
  Did you play with only one eye open, or just one contact lens? I have worse vision than you (-8.0, -7.50), and I know that I can still function with just one lens in of needed. You definitely still have stereo vision even if one input is blurred. Your brain does quite a bit of compensation, and I can imagine if you operated this way for months that your brain would be even better at assimilating the noisy information from your "bad" eye.
  - PhasmaFelis 8y ago
    Sulam is basically correct. I was born with strabismus (my eyes don't focus on the same point). To avoid perpetual double vision, my brain compensates by basically only using one eye at a time. It switches automatically when I'm looking to the side, and I can also switch consciously. (My color perception is very slightly different in each eye, it's weird.) It turns out that stereovision is the least important of several depth cues humans use, and is only really effective out maybe 10 feet or so--beyond that the parallax is too small to give much useful info, and we rely on apparent size, relative motion, surrounding context, etc. I can catch a ball just fine, as an adult. It's really only an issue within arm's reach, and then only when I'm distracted. Occasionally I'll reach for something without paying attention and miss by, like, a foot. Also, I can't use 3D glasses. (With the new polarized kind I can at least wear them and see a normal 2D movie. With the old red/blue kind, everything would be either red or blue, depending on which eye I was using.)
    - 8y ago
ozzmotik 8y ago
i would argue that we don't see in any dimension, at least in terms of the physical capacity of the eye. we just take in varying wavelengths of light and those have no intrinsic dimensionality to them per se. the actual manifestation of dimensionality is, at least in my opinion, merely a construct of the brain. while I think it's accurate to represent reality as a multidimensional thing mathematically and formally, i don't know if dimensionality is an intrinsic feature of it or just a way of categorizing our concept and experience of it. either way, the fact of the matter is that the eye merely takes in raw photons and passing messages on to the brain based on the frequency and intensity of the light, and after saying that i suppose i would be willing to admit that the core nature of light and waves in general is two dimensional, since a wave is defined in terms of frequency and amplitude.

bunderbunder 8y ago

> The problem is that we don't actually see 3D, we basically see 2D twice. Most of us do. But people who only have sight in one eye have no difficulty perceiving three dimensions. And some fairly large percentage of people with binocular vision are stereoblind, typically without even realizing it. If anything, I'd say it's not that > We're aided in converting our 2x 2D sight into 3D mental models through the use of color and parallax. so much as that we're aided in converting our 2D sight into 3D mental models through the use of stuff like color and parallax through the use of stereopsis.

lostlogin 8y ago
As you mention, binocular vision is lacking in a surprising number of people and until recently this was thought to be uncorrectable if not treated while the child was still young. That turned out to be not entirely accurate. Those without binocular vision can have a fairly large range of non-specific symptoms and perception problems. There is an interesting discussion of the change in understanding in this link. http://www.strabismus.org/all_about_strabismus.html http://www.strabismus.org/all_about_strabismus.html

sulam 8y ago

FWIW this is really not true. (The bit about stereo vision being required to see 3D.) When I was in college I was fairly decent on the ping pong table, call it high amateur. I also have very very bad vision - -5 diopters in one eye and -6 in the other. At the time I wore contacts and I was also really really poor. At some point I lost one of my contacts and for six months I was effectively blind in one eye for the purposes of ping pong. It took me about a month, but fairly quickly I was playing at my old level without anything close to stereo vision.

dsnuh 8y ago
Did you play with only one eye open, or just one contact lens? I have worse vision than you (-8.0, -7.50), and I know that I can still function with just one lens in of needed. You definitely still have stereo vision even if one input is blurred. Your brain does quite a bit of compensation, and I can imagine if you operated this way for months that your brain would be even better at assimilating the noisy information from your "bad" eye.
- PhasmaFelis 8y ago
  Sulam is basically correct. I was born with strabismus (my eyes don't focus on the same point). To avoid perpetual double vision, my brain compensates by basically only using one eye at a time. It switches automatically when I'm looking to the side, and I can also switch consciously. (My color perception is very slightly different in each eye, it's weird.) It turns out that stereovision is the least important of several depth cues humans use, and is only really effective out maybe 10 feet or so--beyond that the parallax is too small to give much useful info, and we rely on apparent size, relative motion, surrounding context, etc. I can catch a ball just fine, as an adult. It's really only an issue within arm's reach, and then only when I'm distracted. Occasionally I'll reach for something without paying attention and miss by, like, a foot. Also, I can't use 3D glasses. (With the new polarized kind I can at least wear them and see a normal 2D movie. With the old red/blue kind, everything would be either red or blue, depending on which eye I was using.)
  - 8y ago

ozzmotik 8y ago

i would argue that we don't see in any dimension, at least in terms of the physical capacity of the eye. we just take in varying wavelengths of light and those have no intrinsic dimensionality to them per se. the actual manifestation of dimensionality is, at least in my opinion, merely a construct of the brain. while I think it's accurate to represent reality as a multidimensional thing mathematically and formally, i don't know if dimensionality is an intrinsic feature of it or just a way of categorizing our concept and experience of it. either way, the fact of the matter is that the eye merely takes in raw photons and passing messages on to the brain based on the frequency and intensity of the light, and after saying that i suppose i would be willing to admit that the core nature of light and waves in general is two dimensional, since a wave is defined in terms of frequency and amplitude.