by smusamashah
0 subcomment
- Discovered Maxwell's Spot illusion while looking further into this https://www.psy.ritsumei.ac.jp/akitaoka/Maxwell_spot_illusio...
This is a flickering blue/green image. In the center wherever your eyes are looking, you will see a dark spot.
- It's not possible to smoothly move your eyes unless you are tracking a moving object. Your eyes always move in saccades (quick jerky movements), unless there is a smoothly moving object, in which case your eyes gain the ability to track it smoothly.
https://www.shadertoy.com/view/tXSBWt
Here is a version with a smoothly moving red circle; notice how you can now move your eyes smoothly around the screen as you track the circle.
by marginalia_nu
1 subcomments
- Fascinating. I get very different results depending on which glasses I use.
I'm far-sighted with a relatively weak prescription.
Without glasses I have a tiny bit of lazy eye, it's not really perceptible for the most part looking at me, but for stuff like this I get a sort of figure-eight shaped blob of motion that skips around a fair bit which I guess is because my eyes fail to track correctly and can't find anything to focus on. Can't perceive the motion outside of this area.
With my regular glasses this there's still some of this effect, but much less pronounced. Can't see any motion outside of the center of my field of view.
With my reading/screen glasses, which technically makes me myopic, I get a large perfect circle, and can still detect a lot of motion outside of the circle, even if it's "low FPS".
- Shadertoy got hugged to death by this shader a few years ago and it had a custom "please go away" banner for a little while. Funny seeing it show up again on HN front page.
https://web.archive.org/web/20210430091013/https://www.shade...
by Arete314159
6 subcomments
- Hi, I don't know what this is supposed to do, but I get pretty bad migraines and loading the page made me feel extremely strange almost immediately so I closed it.
I would check to make sure this can't trigger migraines or seizures. Maybe it's just me, but also, please double check.
by ludicrousdispla
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- It's important to point out that all of the crosses are rotating, so this is effectively showing which parts of your vision are susceptible to change blindness (which is effectively 99% of it).
by pixelpoet
1 subcomments
- Hah, so my comment here spawned a post: https://news.ycombinator.com/item?id=45904434
- I first thought the spinning was an optical illusion, like https://www.nationalgeographic.com/science/article/how-our-b.... But in this case the spinning is real and you don’t see the rotation except in a small area (your fovea).
by qwertytyyuu
1 subcomments
- woah its incredible how quickly i can spot the fuzzy spot around where i can clearly see the rotation, and when i unfocus can see fuzzy movement all around.
This is really cool. So this is the theory beind foveated rendering/streaming
- A fully psychometric version of this that explores more than just the fovea could be created by varying the scale parameter (if you crank it up high enough you can see the movement in the periphery). The additional component you would need is to have trials where the subjects has to report whether a particular region (could even be cued with a red circle, I don't think it needs to be random) is actually moving or not while fixated on the center. There are clearly cells that detect this kind of motion in the periphery but they need larger visual input, possibly because the receptive fields of the cells that feed in are larger out there.
- The site is unavailable, because it is infected with cloudflare.
by smusamashah
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- The links seems to be down. From what I gathered, this is its video https://www.youtube.com/watch?v=3RUcQV3rd9k
by wartywhoa23
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- I wish there was an url parameter to share this fullscreen right away!
UPDATE:
And yep, there (mostly) is!
https://www.shadertoy.com/embed/4dsXzM?gui=false&paused=fals...
by cornonthecobra
2 subcomments
- At the default scale of 90, I can't see anything spinning at all even with the video full screen. If I set the scale to 250 or larger I can see the stars spinning, but I just see the whole field spinning. Even if I get so close to the screen it almost fills my field of vision.
So for me either the stars are too small to see any motion, or I can see them all spinning no matter what.
What effect am I supposed to see?
by BriggyDwiggs42
2 subcomments
- Does anyone know how the hell this works
- What kind of sorcery is this? Incredible visualization!
- The idea is to look at the scene and observe which crosses are rotating. You will notice that in your peripheral, the crosses appear not to rotate (although they are, and you can check that by focusing on them). This gives you an idea of how large your fovea is.
On a retina Mac I had to double the scale value to get reasonable results.
by danielvinson
1 subcomments
- I can't see any movement, at any distance. How likely is it something weird with my vision vs. something weird with my monitor/computer? I'm on a 360hz monitor at 2k.
- Oh wow, this made me realize something I've had for 20 years: When I look too close for a few seconds, I get blurriness at the center of my vision. It goes away after a while, but this made me realize that the blurry region is actually my fovea!
I have no idea why my fovea blurs when I look close up at something, and doctors haven't been able to figure it out, but at least now I can google it better.
- I have nystagmus (rapid, uncontrollable, rhythmic eye movements), so I couldn't see anything at first, just lots of small dots.
I had to zoom in (Mac accessibility tool) but then I could see the effect briefly. My eyes go everywhere, but I could see patches of moving shapes with stationary shapes further away, only that the patch moved around a lot!
by willbicks
1 subcomments
- This is a truly incredible demo.
- Awesome. You'll see the little stars rotating only in the area they reach your fovea, the most sensible part of the retina. All the rest will not be able to perceive any motion.
- does your brain just give up when the little stars seem to be still until you focus on one/a few
oh I see fovea
by burnt-resistor
0 subcomment
- Have monofixation syndrome, so I can't see this or stereograms.
by astroflection
0 subcomment
- I get about 4cm wide at 50cm distance.
- That's how small the high quality input to your neural network is.
All your smart neurons start their inputs there (let's skip hearing for a moment). Every time you did math it worked on neurons with their roots at this small bunch in the visual cortex.
It's a tool for reusing training data. When you move your eyes around same neurons are fed new data samples.
It's basically same trick that convolutional neural nets use.
- This would make for a cute screensaver
- I don't get it, all I see is:
"Bad request"
am I missing the joke?
- ok, i dont get it.
on my phone at typical distance and 90 scale i only see about an asprin tablet size area spinning. but at 180 scale i see almost everything spinning at same distance.
i think peripheral vision is quite sensitive to movement/contrast changes, but the moving shapes have to be large enough to trigger those receptors?
not sure what to conclude from this.
by altairprime
3 subcomments
- What’s the correct scale for 210dpi?
- This is quite cool, rocked back and forth from and to my screen and got a (bit inconsistent, but consistently visible) "shape" of the fovea. maybe 30% larger than I thought it'd be!
Right after though, I felt like my vision was clouded, like there was a grey overlay on it or something for a few minutes. Don't recommend having this open for too long. Visual cortex doesn't like running against its limits I guess
by herodotus
3 subcomments
- Amazing - but iPhone screen is too small. Works on my iPad.
by pacoverdi
4 subcomments
- Reminds me of this app that is supposed to clear up your brain when staring at the screen for a while
https://www.paulkeeble.co.uk/posts/cff/
- TL;DR it helps you identify the true diameter of your visual focus, which is said to shrink with old age (mine shrinks more in terms of _time_ dimension but that's a different issue!)
For best results, use it _fullscreen_, change the #define `90` values to a higher value if you're on a high dpi screen.
Stare at a few places on the screen and you'll get the effect of appearing to rotate only where you stare.
It's pretty neat.
by VeritySage07
0 subcomment
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