[HN Gopher] Using the moire effect to show different arrows to e...
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       Using the moire effect to show different arrows to each observer
       (2018)
        
       Author : raldi
       Score  : 117 points
       Date   : 2024-09-01 16:06 UTC (6 hours ago)
        
 (HTM) web link (www.popularmechanics.com)
 (TXT) w3m dump (www.popularmechanics.com)
        
       | hammock wrote:
       | How far can this be taken?
       | 
       | Can you create a lenticular-type image with this?
       | 
       | Can you use a variable moire effect to create motion graphics?
        
         | taejo wrote:
         | > Can you use a variable moire effect to create motion
         | graphics?
         | 
         | Yes! https://www.creativebloq.com/animation/moire-effect-
         | book-714...
        
         | hyperific wrote:
         | https://actu.epfl.ch/news/harnessing-the-moire-effect-to-mak...
        
         | msk-lywenn wrote:
         | Buenzli/Demodays OHP (overhead projetor) competition has many
         | of those
         | 
         | https://www.youtube.com/watch?v=6G5rTavyx7A
         | 
         | https://www.youtube.com/watch?v=AZ39obFzaQs
         | 
         | https://www.youtube.com/watch?v=LCIsIfEOEI8
        
           | IshKebab wrote:
           | That's equal parts hilarious and impressive. At least the
           | first one. Some of the others were hilarious and
           | embarrassing:
           | 
           | https://youtu.be/LCIsIfEOEI8?t=134
        
         | nicd wrote:
         | This also reminds me of Lumii (now Fathom), which is an MIT
         | media lab spin-out that prints multiple inkjet layers to create
         | a 3D effect:
         | 
         | https://www.inkworldmagazine.com/contents/view_online-exclus...
        
         | dahart wrote:
         | Tons of interesting applications
         | https://en.wikipedia.org/wiki/Moir%C3%A9_pattern#Implication...
         | 
         | I saw a good talk a couple decades ago where the speaker clued
         | us into how with moire interference patterns, translation of
         | one pattern turns into translational motion of the interference
         | pattern that is 90 degrees offset (e.g., move one grating to
         | the left/right, and the result moves up & down), and a rotation
         | of one grating against another becomes scaling of the resulting
         | pattern. He had lots of neat examples of animation, hidden
         | designs, magnification, moving text, morphing images, etc. I
         | couldn't find a link immediately, but he was working on a
         | textbook explaining the theory of generalize Moire patterns.
         | With just a little searching, I do see lots of that kind of
         | stuff describing mathematical and perceptual properties and
         | various uses of Moire effects.
        
       | diggan wrote:
       | What's the difference between the Moire effect and "Lenticular
       | printing"? https://en.wikipedia.org/wiki/Lenticular_printing
       | 
       | The effect seems to be very similar, but the Wikipedia page I
       | linked doesn't describe itself as using the Moire effect.
        
         | downboots wrote:
         | In Moire patterns the lines are not parallel (they don't even
         | have to be lines), and there is no lens. But now I'm tempted to
         | combine the effects.
        
       | cwillu wrote:
       | This is more or less how airport glide slope indicators work.
        
         | knodi123 wrote:
         | https://en.wikipedia.org/wiki/Precision_approach_path_indica...
        
       | dublinben wrote:
       | This is nothing but blogspam of the embedded Tom Scott video:
       | https://www.youtube.com/watch?v=d99_h30swtM. This article adds
       | nothing that is not already included in the video itself.
        
         | jimmaswell wrote:
         | It is nice to get a good gist without committing to a video
         | sometimes.
        
           | lisper wrote:
           | Unless is a Tom Scott video. Those are almost always worth
           | the investment.
        
             | serf wrote:
             | some people just don't watch youtube.
             | 
             | someone that's a quarter-of-the-way proficient at speed
             | reading can read a short article like this in seconds --
             | without the time investment or the need to buffer video
             | data to read the transcript.
             | 
             | every media has a place, generally speaking the trivia and
             | background included in a YT video is interesting -- but in
             | the end it's Jeopardy answers and brain-candy for me 90% of
             | the time.
        
           | omoikane wrote:
           | I use the "show transcript"[1] function for that.
           | 
           | [1] In the web (desktop) version of youtube, if you expand
           | the description, there is a "show transcript" button near the
           | bottom. Not sure about mobile or other versions.
        
         | planetpluta wrote:
         | I appreciate being able to quickly skim an article rather than
         | watch a video - especially when in public without headphones!
        
           | niccl wrote:
           | definitely agree. the information density of well written
           | article (or even 'blog- spam, in this case) is far higher
           | than almost any video
        
         | lucideer wrote:
         | I don't think you can count something as blogspam unless it's
         | rehashing something in the same medium as itself. Video to text
         | is fine imo.
        
           | fsckboy wrote:
           | spam is advertising; blogspam is a blog that appears to be
           | about something, but it's not really (and as a result, it's
           | very thin, regurgitated, etc), it's an attempt to lure you
           | into a relationship with a predator
           | 
           | this particular article is not a good replacement for the
           | video, it adds nothing, it subtracts some things... but the
           | video also doesn't say all you want to hear either. The
           | article could have used a small animated gif like one might
           | see in a wikipedia article. It would be very nice to see what
           | simple patterns when overlaid would give you >> and << from
           | different angles.
        
         | bookofjoe wrote:
         | I never watch embedded YouTube videos so this is definitely NOT
         | blogspam for people of my ilk.
        
           | chinathrow wrote:
           | I think OP means the blog does not add value compared to the
           | original video everyone can watch on YT directly.
        
             | bookofjoe wrote:
             | Ah. Can... but prefer not to in my case. See, for example:
             | 
             | https://moglen.law.columbia.edu/LCS/bartleby.pdf
        
               | al_borland wrote:
               | I threw this in some AI to have it summarized. I'm not
               | sure what this has to do with watch watching videos on
               | YouTube. Care to explain your key point, rather than
               | hoping people can glean it from a 30 page metaphor?
        
               | bookofjoe wrote:
               | I would prefer not to.
        
             | ranger_danger wrote:
             | Not everyone can watch youtube videos, it could be blocked
             | in your country or they could be blind for example, and I'm
             | sure there's more reasons. Some people also just prefer to
             | read instead.
        
         | raldi wrote:
         | I'm cool with having that link swapped in.
        
         | IshKebab wrote:
         | I mean in fairness the 3:53 video is about 3 minutes longer
         | than necessary.
        
         | darajava wrote:
         | Yes but if OP posted the video it would have been killed by
         | HN's filters.
        
       | mattyturner wrote:
       | I used to walk past that very same light from time to time and
       | wonder what it was used for around 20 years ago. Thank you
       | internet/HN!
        
       | xipho wrote:
       | There is an concept in this video that perfectly encapsulates why
       | taxonomists (in this case those who describe Earth's
       | biodiversity) are so critical, and why their work has the impact
       | it does. The exercise is left to the reader...
        
       | thih9 wrote:
       | Related, "An Evaluation of the Inogon Leading Mark"[1]:
       | 
       | > Responses from the field evaluation were generally negative,
       | mostly because the device was perceived to have too short a
       | detection range for the Constable Hook Channel. It is recommended
       | that the device be considered as a candidate range light for very
       | short range applications.
       | 
       | [1]: https://apps.dtic.mil/sti/citations/ADA168108
        
       | cypherpunks01 wrote:
       | _When a grid 's misaligned_
       | 
       |  _With another behind_
       | 
       |  _That 's a moire_
        
         | dredmorbius wrote:
         | Credit where due: <https://www.xkcd.com/1814/>
        
       | red_admiral wrote:
       | The older way of doing this is simply to have several pillars in
       | line, each one a bit higher up than the previous one as you move
       | away from the shore. I think they're usually painted white with a
       | red band or something.
       | 
       | From a ship, if you see the pillars in a straight line ahead of
       | you, you're in the channel; if the rear pillar is to the left of
       | the front one from your viewpoint you're too far left.
       | 
       | The vertical version of this is the visual approach indicator for
       | aircraft: red and white pairs of lights with flaps at different
       | angles so that if you're too high, you see all white, and if
       | you're too low all red. On the exact glide path you see both red
       | and white.
        
         | stn8188 wrote:
         | This is the method I've always seen here in the US, where we
         | call them range lights [0]. There are lights for night
         | alignment and striped boards for daytime. Many years ago I used
         | to maintain these systems in the Caribbean and the Long Island
         | Sound with the US Coast Guard.
         | 
         | [0] https://en.m.wikipedia.org/wiki/Leading_lights
        
         | nobodyknowin wrote:
         | We do the same concept in night diving. Set a glow stick with a
         | pie tin low, and another high behind and above it.
         | 
         | Then when you come up from the dive you can see which way you
         | need to swim along shore to exit where you entered.
        
       | mensetmanusman wrote:
       | Once you know about this effect, you see it everywhere.
       | 
       | No one wears finely striped shirts for movies because of it.
        
       | ranger_danger wrote:
       | >it will always display an arrow or series of arrows (sometimes
       | strange, distorted ones) pointed in the direction you want them
       | to go
       | 
       | How does it know which direction is correct?
        
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       (page generated 2024-09-01 23:00 UTC)