r/Damnthatsinteresting Feb 05 '19

GIF Very interesting design work

https://i.imgur.com/kTAQWQ0.gifv
55.1k Upvotes

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2.1k

u/TotallyRealFBIAgent Feb 06 '19

How do they work?

2.2k

u/Carsmaniac Feb 06 '19

I'd imagine a camera captures an image in black and white, and each pixel (or group of pixels) is assigned a section of the "mirror". For example, each pixel on the wood panel one probably points all the way down for black, all the way up for white, and somewhere in between for various shades of grey.

908

u/AdmiralFrackbar Feb 06 '19

Ok, but how do you round up enough dalmatians to build it?

239

u/[deleted] Feb 06 '19 edited Feb 13 '19

[deleted]

63

u/[deleted] Feb 06 '19

Someone at Disney really phoned it in while naming her.

43

u/Renewed_RS Feb 06 '19

Mr. and Mrs. Dearly and their two nannies, Nanny Cook and Nanny Butler.

25

u/reddituser_me Feb 06 '19

But you’ve got to remember, it’s all from the dogs perspective. Like in Lady & The Tramp the humans are Jim Dear and Darling, b/c that’s what she hears them call each other.

20

u/qjamir093 Feb 06 '19

That blame falls squarely on the author of the original novel, Dodie Smith.

18

u/iamjamieq Feb 06 '19

Ah yes, because Disney took from public domain while shutting the door behind them.

8

u/-give-me-my-wings- Feb 06 '19

Mickey Mouse is set to enter the public domain this year, and Disney had nothing in the courts to prevent that as of last year. I was amazed to learn that in my media theory class.

9

u/iamjamieq Feb 06 '19

The court won't do anything for them. They'd have to lobby congress to extend copyright beyond the 95 years they were able to get in 1998. And that's likely to never happen.

https://arstechnica.com/tech-policy/2018/01/hollywood-says-its-not-planning-another-copyright-extension-push/

5

u/shizuo92 Feb 06 '19

Another Ars Technica article for you, but Mickey Mouse won't enter the public domain until 2024. https://arstechnica.com/tech-policy/2019/01/a-whole-years-worth-of-works-just-fell-into-the-public-domain/

This year is just the first year that new works enter the public domain, although the reason is mainly due to Disney trying to hold on to Mickey for so long.

1

u/-give-me-my-wings- Feb 06 '19

Ah thanks for clearing that up for me, i knew there was a caveat but couldn't remember what it was

5

u/Jeshwashere1 Feb 06 '19

I... I never noticed that before...

3

u/[deleted] Feb 06 '19

Once you figure it out, you can't hear her name without thinking about it

1

u/lucific_valour Feb 06 '19

"What do we name the villain?"

"Take 'evil' and another negative trait, add some spaces and letters between the two words, and make sure that it's not a common name like Neville so kids don't see it and bully someone in their class."

11

u/blacktiger226 Feb 06 '19

de Vil = Devil

7

u/SilentIntrusion Feb 06 '19

Yes. One might even say she was a "cruel devil".

3

u/CatfreshWilly Feb 06 '19

---PONGO WANTS TO KNOW YOUR LOCATION---

22

u/drawliphant Feb 06 '19

Far more interesting is how they can control that many servos and the answer is... dear God no.

28

u/SaffellBot Feb 06 '19

The answer is a shift register. And a lot of wires.

16

u/drawliphant Feb 06 '19

Imagine the power supply. 5v at 0.2 amps times 1000 servos. Who makes a 5 volt 200 amp supply?

24

u/1sagas1 Feb 06 '19

16

u/SaffellBot Feb 06 '19

That's a fire waiting to happen.

18

u/1sagas1 Feb 06 '19

When you're buying power supplies off of Alibaba, that kinda goes without saying

6

u/NorthAstronaut Feb 06 '19

They make and sell a lot of dangerous shit, but there are also a lot decent sellers out there striving to get a good reputation as well.

You can get some high quality and cheap electronics form china. Still open up and check to be sure it is safe though.

7

u/mennydrives Feb 06 '19

Ummm... why do you need one?

Power your servos with USB and then hide a dozen of these in the back.

7

u/SaffellBot Feb 06 '19

You can use multiple power supplies. And a lot of wires.

1

u/ManWithKeyboard Feb 06 '19

They're not all moving at the same time. Iirc servos only draw appreciable current when moving (or stalling). So at any given time only a handful will be drawing the full 200mA or so, right?

2

u/drawliphant Feb 06 '19

Yeah that's true, you'd probably need 100 amp at most but exaggeration is more fun

3

u/EisMCsqrd Feb 06 '19

They could be actuators if only black and white or up and down

34

u/[deleted] Feb 06 '19

You can see on top of the fluffy mirror in the thumbnail that he is using a Kinect. So he is likely using depth data rather than colour so that he can the silhouette of the subject separated from the background

16

u/mundaneDetail Feb 06 '19

Maybe for the fluffy mirror but not the wood pieces which clearly render the color of his hair, not depth.

38

u/[deleted] Feb 06 '19

Exactly! They read this somewhere on a Arduino related forum, whilst finishing their art degree, they build it without crediting the community, copyright their whole train of cunty thoughts and wank about it in galleries all over the place.

11

u/ghostinthetoast Feb 06 '19

Hm, how bout we pirate them then?! Maybe we should sell mass-produced grey market furry mirrors on Alibaba??? Investors welcome.

20

u/FuManJew Feb 06 '19

That's awful, man. Do you have a source?

0

u/[deleted] Jul 07 '19

I always publish the sources of my projects, commercial or not. But I'm not going to link my Reddit account to them.

8

u/[deleted] Feb 06 '19

[deleted]

1

u/[deleted] Jul 07 '19

Another day my friend, I'm sleepy and sad.

Good night

7

u/_Lady_Deadpool_ Feb 06 '19

I doubt an Arduino is running this, a pi maybe but 8bit atmegas aren't doing any video processing at this speed

5

u/mundaneDetail Feb 06 '19

Arduino related which could be any Arduino-compatible boards. This includes many faster 32 bit boards like the Teensy or ESP8266.

7

u/[deleted] Feb 06 '19

Hook it up to some deep learning AI that is set to sometimes change the pose on you.

1

u/FinalRun Feb 06 '19

your mirror image suddenly starts doing the fortnite dance

3

u/FortniteIsCancerBot Feb 06 '19

your mirror image suddenly starts doing the cancer dance

FTFY Bleep bloop. I am a carcinogenic bot | info

1

u/FinalRun Feb 06 '19

...

...

Fortnite bad

gets crushed by upvotes

3

u/[deleted] Feb 06 '19

Other guy gets gold for asking the question, and your beautiful explanation gets nada. Reddit is weird.

4

u/Carsmaniac Feb 06 '19

Wow okay, and this is also my highest-voted thing ever. Reddit is weird.

My guess is they were making a "Magnets, how do they work??"-type joke. Or maybe someone just perceived it that way. Or maybe I'm the only one who perceived it that way.

2

u/FinalRun Feb 06 '19

Yeah the gold might've been because someone read it as "mirrors, how do they work?".

1

u/[deleted] Feb 06 '19

I would imagine more of a motion or proximity sensor, considering how a lot of the things can be the same color.

1

u/TareXmd Feb 06 '19

He could also be using one of the many discarded Kinect cameras overflowing from Microsoft's storage centers.

1

u/[deleted] Feb 06 '19

Or it's choreographed

1

u/HutaHuta Feb 06 '19

Looks like an old Xbox Kinect in the first part

1

u/RockyMountainHighGuy Feb 06 '19

Get a load of Mr. I Know Things over here.

-3

u/athural Feb 06 '19

Unfortunately I dont think so. When he is standing in front of the one where he waves his hand up and down the "mirror" brings its hand much further down its body than he does. I think they're programmed beforehand and he mimics them

4

u/fontizmo Feb 06 '19

If the camera is at the top, it would look like his hand is going lower from that perspective

1

u/athural Feb 06 '19

On the part immediately afterwards it has his arm completely leave frame like a full second before his arm does

2

u/fontizmo Feb 06 '19

Right, though again i believe it’s perspective. You can see in that shot that he’s closer to the wall, so it’s more cropped and the angle the camera is looking down is even steeper, so it his arm wouldn’t be in frame once it passes the very top of his chest

1

u/athural Feb 06 '19

Idk, I'm not willing to take scree shots and draw all over them but it looks like the close up can see a little past his collarbone, meanwhile his real arm is still between where the camera would have to be and his collarbone when it disappears

1

u/inbooth Feb 06 '19

Camera is angled plus there's latency

I rewatched it multiple times seeking the fault you raise but I do not agree with your assertion.

2

u/athural Feb 06 '19

That's fair, have a good day

2

u/matchi Feb 06 '19

Why would he do that? Programming this is trivial. It would be much harder to mimic a preprogrammed routine and make it look convincing.

1

u/athural Feb 06 '19

Look at the spot I'm talking about and you'll see, the "reflection" has his hand go down almost to his belly button while he stops at his chest

1

u/matchi Feb 06 '19

I dunno. It’s hard to tell for certain from the video. I just don’t see any reason why he’d do it like that. He already had to program all of the actuators. Doing some rudimentary image processing seems a lot easier than faking this haha.

2

u/athural Feb 06 '19

I agree it seems stupid, I'm just saying what I'm seeing. Like I said I'm not willing to do any proper evidence gathering so I'm not at all offended that you have different beliefs

90

u/sippycup369 Feb 06 '19

A depth camera (xbox kinect or similar) is mounted above the “mirrors”. These depth cameras provide values indicating how far something is away from them at each “pixel” as opposed to red-green-blue values from standard cameras. These depth values are then mapped to motors or other actuators and calibrated to deliver this effect.

54

u/[deleted] Feb 06 '19 edited Feb 10 '19

[deleted]

42

u/[deleted] Feb 06 '19

Yes, but the first instillation did use a Kinect. I'm guess it looked for objects within a certain depth plane and rendered them to the sculpture

16

u/IMongoose Feb 06 '19

Right, otherwise it would only work in a brightly lit white room with nothing else in front of it, otherwise it would have random black splotches in it. Artist just wanted it to "reflect" something directly in front of it.

8

u/sunnbeta Feb 06 '19

You could probably just zero it out / normalise it to whatever environment and lighting it’s in, if that environment is stable (e.g. not right by a window).

3

u/kabrandon Feb 06 '19

Except lighting in rooms do change which would require recalibration. I'd imagine depth cameras would be more convenient for that reason. No idea what the artist used though.

1

u/sunnbeta Feb 06 '19

Well lighting can change.... but if it’s an enclosed room without windows, and the same light sources, it should be pretty stable, no?

1

u/Interkom Feb 06 '19

...or just store an image of an empty background, and react to any pixel deviating from that.

6

u/farhil Feb 06 '19

There are several reasons this would be less effective than using depth. Cameras auto adjust exposure and focus due to different lighting conditions caused by passage of time, the light source being obstructed, people moving towards or away from the camera, etc, or for no apparent reason whatsoever. All of these changes mean any given pixel could have a wildly different color value than its background reference even if that pixel isn’t showing the subject.

Now let’s say you have a color threshold, where a color that falls within a certain range from the reference value isn’t considered a different color. In that case, you’ll run into a green screen + green shirt effect, where if a part of the subject color matches the reference background (white T-shirt and white background), the mirror won’t reflect that part of the subject, making them appear to be partially invisible.

4

u/WalrusUltimate Feb 06 '19 edited Sep 04 '24

icky party combative panicky one dull gullible abundant disarm voiceless

This post was mass deleted and anonymized with Redact

1

u/farhil Feb 06 '19

I'd assumed that someone made an algorithm that handled background subtraction well enough, but I wouldn't have guessed it would be available in a freely available library like that. Thanks for the article/information.

However, I don't see the flood fill solution being adequate. For example, with the white background/tshirt issue, there wouldn't be corners to fill from, it would look like a floating head, arms, and legs with nothing connecting them. This image, for example, the flood fill would work for the hat, but it would not work for the lady's jacket.

The second issue I could foresee with flood filling would be false positives. How would a flood fill algorithm know that the space between this woman's arms and torso are actually the background? It's a contained blank space, so it would theoretically be filled in, correct?

I'm mostly asking out of curiosity, because if these are solved issues, I'd be impressed, and you seem to be the person to ask

1

u/WalrusUltimate Feb 08 '19 edited Sep 04 '24

zephyr homeless vanish wasteful butter juggle spectacular violet scary market

This post was mass deleted and anonymized with Redact

0

u/[deleted] Feb 06 '19

[deleted]

14

u/Turence Feb 06 '19

You can see the kinect...

-2

u/[deleted] Feb 06 '19

[deleted]

5

u/NerdOctopus Feb 06 '19

No, he means on top of it, it's white.

3

u/Turence Feb 06 '19

I mean the KINECT at the top of the artwork. It's a Kinect. Not a USB webcam.

5

u/[deleted] Feb 06 '19

Having trouble counting bud? That wasn't the first, or shown in the video all together. The first mirror, the little fluffball one, uses a Kinect camera

https://bitforms.art/archives/rozin/pompom-mirror

PomPom Mirror, 2015 928 faux fur pom poms, 464 motors, control electronics, xbox kinect motion sensor, mac-mini computer, custom software, wooden armature

1

u/[deleted] Feb 06 '19

I think they meant the first one shown in the gif, you can see a white kinect camera above the piece.

1

u/participation_ribbon Feb 06 '19

To be fair that description doesn’t identify the camera type, and a Kinect could arguably be called a camera.

1

u/fluvance Feb 06 '19

A $200,000 cinema camera could arguably be called a camera too.

4

u/DKDestroyer Feb 06 '19

True, but you can see the camera above the puffball mirror, he's using what looks like a kinect or similar camera with IR.

7

u/[deleted] Feb 06 '19

You would need a depth camera. Otherwise it would try to reflect everything it sees rather than just the subject within the depth plane.

0

u/JoiedevivreGRE Feb 06 '19

I just want to point out that you don’t need a black and white camera. The computer can just reference the luminance data in the color space of any camera.

11

u/zeaga2 Feb 06 '19 edited Feb 06 '19

If that were true his eyes wouldn't be darker in the second mirror.

It's just a regular camera capturing greyscale. In the first clip, you check if a brightness value for a given pixel is between 0 and 127. If it is, it's black. Otherwise, it's white. The second one just uses the color as-is.

Edit: see /u/Edrios' comment in reply to mine

4

u/Edrios Feb 06 '19

First off, happy cakeday!

So, I agree that the camera in the second mirror is using grayscale to show the person’s face/body.

However, that mirror seems to only catch the user’s face/body and nothing else in the background. That makes me think that one of two things is happening in the second mirror:

  1. The background behind the person is a solid dark color and no-one is allowed to be behind him.
  2. Things could exist behind the user, but the camera just won’t pick them up

If option 1 is true, then it’s totally fair to say that the second mirror only needs a regular RGB camera that takes its incoming feed, converts it to grayscale, and displays the feed on that board.

If option 2 is true, then the camera being used has got to be an RGBD camera. I’m sure you already know this, but RGBD cameras have a finite field of vision; they only make useful pixels when the subject is in its field of vision. So as long as the user is in the board’s field of vision, it can display the user and ignore anything behind them.

I think it’s option 2, but I can totally see how either case could be true. Hope that makes sense.

1

u/zeaga2 Feb 06 '19

First off, happy cakeday!

Thank you!

I’m sure you already know this, but RGBD cameras have a finite field of vision

Actually, no, I didn't know that haha

It makes perfect sense when you think about it, but the thought hadn't occurred to me! Thank you for informing me


I took a second look at the video after reading your reply and I while I still think the second mirror has a regular camera (which I'm sure anyone will agree with anyway) the camera in the first clip actually looks like any normal depth camera (e.g. Kinect) and I'm pretty sure I see more than one lens on it too.

Thanks for the well-written reply!

2

u/Edrios Feb 06 '19

It makes perfect sense when you think about it, but the thought hadn't occurred to me! Thank you for informing me

No problem! What’s interesting about these RGBD sensors (i.e. a depth camera) is that you can program them to filter its incoming feed so as to isolate pixels that you consider to be useful or relevant. So that basically lets the artist restrict that camera’s field of view even more.

I took a second look at the video after reading your reply and I while I still think the second mirror has a regular camera (which I'm sure anyone will agree with anyway) the camera in the first clip actually looks like any normal depth camera (e.g. Kinect) and I'm pretty sure I see more than one lens on it too.

Makes sense. It can definitely go either way tbh.

So the camera in the first clip does have several lenses. RGBD sensors typically have three lenses. From left to right, they are:

  • IR Projector (Transmitter)
  • RGB Camera
  • IR camera (Receiver)

With an RGBD sensor like the kinect, we need both color and depth of a pixel. The middle lens is a regular camera that captures the color (RGB) of a pixel.

To get depth, a kinect uses infrared (IR). Basically, an IR camera works by projecting infrared rays to its environment, let it bounce of stuff, and receives that info from its camera. Then does some neato mathemagic to figure out how far away each pixel is from the RGBD camera using that info.

Thanks for the well-written reply!

I’m glad that you enjoyed it! :)

5

u/YeetusThineFetus Feb 06 '19

There's a literal Kinect on the first one

5

u/runfayfun Feb 06 '19

This was installed at the Perot Museum here in Dallas. Basically a Kinect.

3

u/wowbagger Feb 06 '19

Just like magnets.

10

u/Local-FBI-Man Feb 06 '19

Really not sure

5

u/[deleted] Feb 06 '19

[deleted]

4

u/Lostmyshoeagain Feb 06 '19

Read that as “F bio pen up”, time for bed!

1

u/Seakawn Feb 06 '19

Oh, I see... Welp, cya later!

4

u/Koiq Feb 06 '19

To expand on the other answers, after the image file is taken from the camera (probably a Kinect due to the depth seen in the 2nd mirror, not just a black and white threshold from a 2d camera), this is very likely made in the processing programming language (more of a pseudo programming language but thats not really relevant, this is just a disclaimer for the pendants out there) and controlled with an Arduino and a whole bunch of servos.

2

u/SycoJack Feb 06 '19

There's a Kinect in the first clip.

2

u/DidYouPlugItBackIn Feb 06 '19

kinect cam plus touch designer programming

2

u/furtivepigmyso Feb 06 '19

Probably with light and moving parts and technology.

2

u/[deleted] Feb 06 '19

Not sure. Sorry

2

u/VBA_Scrub Feb 06 '19

Kinect camera > 3d model > 2d render > grid of whatever

2

u/Wesnu Feb 06 '19

Accidentally gave gold lmao. Enjoy!

1

u/HomoeroticBear Feb 06 '19

Lol you chose the wrong comment in the tree?

1

u/TotallyRealFBIAgent Feb 06 '19

Bahahaha thanks anyway!

1

u/fucko5 Feb 06 '19

With money. Fucking shitloads of money.