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Comment by worewood | Hacker News Reader

Well, we see the world as a 2d projection BUT we (usually) have 2 eyes so we have some amount of 3d-info.

Maybe mario has 2 eyes too, which would give him some amount of 2d-info. (Just like an MRI can construct a 2d slice from 1d info). So the first person game should have maybe a depth info on those pixels.

What I mean, mario does not see only a line. He sees a silhouette of what lies ahead of him.

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I think it would require one eye above the other to have depth perception in his 2d world.

Eyes can’t even be side-by-side as that axis doesn’t exist.

Having said that, the human brain is capable of reconstructing a 3d perception with only one eye through learnt understand and interpreting the picture change over time as you move. I image it’s the same for Mario, but in 2d.

> I think it would require one eye above the other to have depth perception in his 2d world.

Is his world actually 2D though? Or a 3D world projected down to 2D? The latter is what I would expect.

The specific restrictions on his movement would seem oddly coincidental if he’s in fact in a 3D world that we just happen to be seeing projected in 2D.

He can move behind some objects though, such as flags, which indicates there is more than one pixel width in that plane.

This does not work with going down the pipes, since he disappears "into" the pipe (so behind the front part of the pipe)

Yeah, as someone with a lazy eye 3d honestly isn't much different than 2d.

Due to various issues my eyes don't work together (I look out of one of the other depending on a mix of focal length and just what my brain randomly choses), but we get 3D information from more than just using two eyes in unison. The parallax information that two eyes allows us to infer can also be derived by movement, either of objects relative to each other or by our head movements. Ever watch a cat or other animal lift its head up a bit then resetting prior to a jump/pounce/other, even if the view is clear so they don't need to look over something? That is partly what they are doing, gaining extra accuracy by being able to do parallax computation based on information from four points (both eyes at different heights) instead of two.

But eye don’t really see in 2d anyway. There are plenty of tricks involved in the vision cortex based on how your head moves and how your eye scans and accommodates for its 3d field of view. It’s far more complex than just producing a 2d image for the brain to interpret.

>But eye don’t really see in 2d anyway

So is that a pun, a spelling error or bad english?

I want it to be the former.

In original Mario he does have only one eye though, and it’s on the side of his face?

No, Mario has two eyes. You can see the other when you go the other way.

It's the same eye, you're seeing it from the opposite side of Mario.

To have two eyes there should be some horizontal separation between them, which can't happen in 2D.

So his one eye goes through his face and you see it from both sides. Wonderful

exactly, if mario had stereo vision, it'd have to be his eyes were on top of each other.. And just like how 3D games projected onto a 2D monitor are not much different from their VR counterparts, a 2D game projected into stereo 1D wouldn't be much more interesting either..

I thought about it, how our eyes are placed on the sides, probably because we're very earth-bound, and horizon lies that way and such.. It'd be really interesting if we had an additional third eye on our forehead, it'd give us a bit more detailed depth perception, but I don't think it'd be that much more useful.

Also, human eyes aren't passive sensors like cameras. We move them (consciously and unconsciously) to gather more info as we need it.

And we have a few unconscious abilities like seeing light polarization that can help: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4528539/

Since his eyes are on the side of his head he should only be able to see the perimeter of his eye sockets, if any light managed to reach them. Mario is blind :(

Mario passes in front of things like backgrounds and similar. Since there is a notion of over/under, he lives in a two dimensional world.[1]

[1] https://en.wikipedia.org/wiki/Super_Mario_Bros.#/media/File:...

What proof do you have that he isn't displacing the supposed "background" like a bacteria moving in a petri dish?

Calvinball rules say the volume of bushes, as a liquid, aren't compressible. Pixels are not moved, outline is overlaid by the body without surrounding the body.

Perhaps they are transmogrified?

Then Mario is above them during the transmorgrificalization.

2D Mario doesn’t have two eyes, he has one. If he is drawn with two eyes the second one would be inside his body and would not see anything as it’s view is blocked by pixels.

If we take it further, even the eye "we" can see is blocked by the bridge of his nose, so I doubt he actually sees anything.

I wonder if that’s why he needs someone else to control his movements.

What would the people in a Picasso picture see?

There’s one for Dall-e Mario level as painted by Picasso

Or Dali

this is the kind of arguments I come to Hacker news to read about.

It's beautiful

If you look at the initial zoom, his eye actually lies within his head, so it’s unclear how he can see anything at all.

That is strange.

Semi-transparent head, probably. But it means he can only see light intensity, which is why he falls into holes and runs into dangerous objects on the regular.

You can see Mario has two eyes on his death animation, though.

Well, the site itself says

> we decided that we needed to see the world from his eyes.

;-)

I think it might be super interesting to use width to represent depth of the pixel.

In the game Mario clearly has two eyes, side-by-side like our own. How did he evolve this feature if there is no benefit in his world?

Evolution isn't necessarily perfect, just good to enough.

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