## 2D or 3D?

you find it to be a stretch because vision is such an intricate process of 2D information processing before 3D representation occurs?

 Quote by RW2012 you find it to be a stretch because vision is such an intricate process of 2D information processing before 3D representation occurs?
I find it to be a stretch because the images we receive are two dimensional and we make inferences that allow to get a rough idea of their 3-dimensional arrangement, similar to how we infer information about depth when looking at a TV screen. We see 2-dimensional images; everything after that is the brain guessing.
 but without the 3d space and our 3d composition and the 3d realm we exist in there would not be the 2d optics that we use to create 3d. 2d is almost a subcategory of 3d in a sense. would you agree with this?

Mentor
 Quote by RW2012 maybe i am misunderstanding you. do you see 3D when you close one eye?
No, I misread you --- you said when you close one eye and I read "eyes". Sorry.

When you close one eye, you can, intellectually, detect signs of depth. Perspective, for example. But as an artist, you should recognize that in art, perspective is used in order to make what is 2d (a photo/painting) appear 3d, it doesn't make it actually be 3d. It is only a simulation, not real 3d. With one eye open, you can't detect a difference between a quality photo and, say, a window. With two eyes open, you can.

Mentor
 Quote by Number Nine I find it to be a stretch because the images we receive are two dimensional and we make inferences that allow to get a rough idea of their 3-dimensional arrangement, similar to how we infer information about depth when looking at a TV screen. We see 2-dimensional images; everything after that is the brain guessing.
I wouldn't go that far. Stereoscopic vision doesn't provide an illusion of 3d, it provides real 3d perception. With stereoscopic vision, you can literally measure depth.
 the brain constructs what we generously call a 3-dimensional representation much later in the visual stream.
While that's true, the place where it is done doesn't change the reality of what is happening: two eyes enable triangulation of distance.

 Quote by russ_watters No, I misread you --- you said when you close one eye and I read "eyes". Sorry. When you close one eye, you can, intellectually, detect signs of depth. Perspective, for example. But as an artist, you should recognize that in art, perspective is used in order to make what is 2d (a photo/painting) appear 3d, it doesn't make it actually be 3d. It is only a simulation, not real 3d. With one eye open, you can't detect a difference between a quality photo and, say, a window. With two eyes open, you can.
so without one eye being used there is degradation.
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For the last hundred years, there has been great debate and strides taken to disavow perspective, and all forms of narrative that you find in paintings made before the advent of photography which made mimicry of the real world in the form of painting a pointless intellectual enterprise.

we can depict 3d space with paint. we then receive the painted info is as 2d in the eye. then we reformulate it back to a 3D representation in our brains. (that's quite a few steps.) in the end, we are still involved with some sort of 3D representation though not of the same type that contemporary artists are weary of. in the end, all things are at one point in this process 2d, flat, surface. yet, a canvas that is painted one color, say flat orange, is not depicting 3d space, but it is still on a 3d armature before it undergoes the process of perception which cannot edit out the perceived fact of it's material weight. in this sense, you cannot escape perspective.

 Quote by russ_watters I wouldn't go that far. Stereoscopic vision doesn't provide an illusion of 3d, it provides real 3d perception. With stereoscopic vision, you can literally measure depth. While that's true, the place where it is done doesn't change the reality of what is happening: two eyes enable triangulation of distance.
so tv creates a sense of space in an illusory space, or in a pictorial space you might call it, as in the case of looking at a photograph of a forest.
 Do we see a 3D world illuminated by 2D photons? => there is no such thing as "2D photons". We perceive a 3D world , even with one eye, in the sense that the image projected on the back of each eye is subject to 3D optical effects as: perspective (further obejcts are smaller than closer ones), blurring (depending on the distance to the focus plane, some image parts may look blurred) Do we see 3D pictures in our minds, or 2D? => The eyes (not the brain!) add a "depth" signal to the color and light intensity by automatically processing parallax (same point seen from two point of vues). However the parallax processing precision decreases with distance, further objects appear to be on a "flat" background. The eyes can add extra signals like outlines and border detection, speed detection etc. This is part of an unconcious processing occuring in the retina (the back of your eye) and the optical nerves However, the brain adds more information to the perceived scene: Knowing the actual size of some objects like human beings, cars , buildings , boats etc. can give you a sense of their distance. That's how one eyed people can drive... Then knowing that light comes generally from above, the brain can add a perception of depth based on shadow analysis. The brain is responsible too for the movement perception by identifying the same image parts in consecutive images (this is used for ciname for example). The brain image analysis can be fooled by optical illusions. Last you must know that the eyes and optical nerves process image information in a manner where the most intense signals (like high speed movements or image part border or bright spots) are sent first to the brain, few ms before the rest.