[Intro drumroll]
Greetings, children. Captain Disillusion, here.
So. You want to know the latest, coolest, most interesting viral thing from last month?
There's this audio clip and depending on the frequency the listener is predisposed to pay attention to,
They hear one of two very ordinary common everyday names
Laurel or Yanny
Which one do you hear? [turns the tape recorder on]
*Explosion*
Holly: I know which one you hear D. It's Yanny, because I hear Laurel and opposites attract.
C.D: Oh joy, Holly's here. Holly: How's my favorite dreamy pixel justice crusader?
C.D: What do you want? Holly: Oh, relax.
Holly: I'm here on official business
C.D: Glad to see you learn to create an artificial body instead of, you know... abducting a corpse.
Holly: I've got a video I want you to explain C.D: Portraits? I don't do portrait videos.
Holly: Oh, come on, it's your favorite kind: simple but perplexing, short, but high-quality, and freshly out of date.
Look. It's a machine that sorts a pile of marbles by color, but there's no electronics.
You just bounce through a bunch of pegs and all fall into the right place. How does it work?
C.D: Since when do you care about techie stuff?
Holly: I've always cared about interesting phenomena be they organic or technological in nature.
C.D: Yeah. Well, it's fake. Holly: No, it's not.
It's just a clever sciencey invention. Are you sure?
C.D: *Clears throat* Yes, I am Holly, how are you not? You don't even have to look that closely, you can just listen.
Thousands of marbles are cascading down through 75 pegs in this contraption; so, why does it sound like only a couple hundred?
I can practically hear the gaps in the waveform between bounces, even though in the picture a bunch of marbles are mid bounce on any given frame.
And toward the end, as the last few marbles fall through, we don't hear fewer individual bounces, just the same continuous sound fading down.
Holly: Okay, but that doesn't automatically prove the video is fake
C.D: No, but it doesn't bode well. And the video side raises plenty of its own questions. What is this thing? How is it constructed?
The conveyor of little claws on the side looks like it's meant to load the marbles back to the top, but there's no axle to rotate it.
How does it hang up there? How's it driven? Same with the hatch that releases the marbles.
Where is the mechanism that opens and closes it?
Holly: Hmm... true. There's not much there, but it looks so realistic.
C.D: Sure, and if you dig up the original video, it even shows what most re-posted versions littering the web don't:
A hand pressing a button to start the drop.
Except it does it in a strange way. When I press a mechanical button, I tend to first train my finger right on it then push for just long enough to trigger it.
This hand lands straight on the button from inches away and stays on it in a frozen pose for a weirdly long time.
Holly: You're not saying the hand is fake?
C.D: It's real, but projected on a 2D plane as part of a complete CG rendering that looks a heck of a lot like the work of Konstantin Otrembsky,
A Russian digital artist who makes animated graphics for television.
Holly: How in the world did you figure that out?
C.D: I Googled it. It's on his YouTube and his Instagram, and even the secret Russian Instagram.
The evidence is pretty compelling wouldn't you say?
Holly: Yeah, I guess...
C.D: What's the matter? Holly: It's just...
I'm dying. C.D: Oh?
Holly: Well, not all the way dying just losing my powers.
It seems fewer and fewer people engage in magical thinking anymore, and without their belief...
I'm just not as strong as I'm used to being.
C.D: Oh.
Holly: But... I remembered you saying, or was it Carl Degrasse Dawkins?
I don't know, one of you brilliant guys. That the real science based world is full of wonders.
That there's greater magic in nature and the cosmos than any fantasy writer could ever dream up
C.D: Yeah, that sounds like something one of us would say.
Holly: So we want to learn it all! Mathematics, biology, physics, teach me! I'm a fast learner.
C.D: Well, that's very admirable. I mean, physics is very much involved in the faking of this video.
Holly: Really? C.D: Yeah, after all it was done with a physics simulation.
When you need to animate a ton of objects falling and colliding with each other, you don't want to do it by hand.
Instead, you set up all the physical conditions for the scene virtually and then run a simulation of what would happen.
Lots of 3D software can run physics sims, but they're not always perfect.
The start of a simulation can be shaky as all the forces suddenly activate.
Some objects might jitter and pop. When the marbles are first released in Konstantin's simulation, one stray one at the top bounces up inexplicably.
Another giveaway of a simulation shows up when something's slightly off in the delicate recipe of scale, gravity, object mass, and other settings.
The hand gives us a good scale reference for the marbles being less than a quarter inch in diameter.
If that's true, these individual bounces seem too high and slow to me. It's as if the marbles are impossibly light or have stronger than normal air resistance
Maybe this was necessary to arc direct them into filling all the slots at the bottom evenly, but artistic license is not valid in the state of believable hoax
Holly: That's so cool. Umm, while you were explaining that I some googling and these things are actually called Galton Boards. They're are all about probability.
How many marbles will fall into each slot, and there's actually a formula to-
C.D: Exactly! So how could this one possibly sort color?
Holly: It can't, it's fake. You're right.
But some people have made some really interesting designs for actual marble sorting devices
There's this brilliantly simple one by pocket83, that just uses gravity to sort marbles by size.
Or this cute one by alexpikkert, which has a color sensor driven by an Arduino board.
I bet if we put our heads together, we could figure out how to build a version of Konstantin's galton board that actually works.
C.D: Yeah, probably. But that's not what he did.
He faked it.
With visual effects.
Holly: Right.
C.D: The question is "how?" What were the steps? And the answer is as follows.
First: He shot an empty background plate. Probably not with a phone,
The rolling shutter is too extreme on those to do accurate motion tracking, which is what he did next.
Then he made a 3D model of the galton board and placed it in the scene. Now, because the marbles are spherical and featureless,
He didn't even have to run a proper rigid body simulation to calculate how they fall. Their rotation doesn't matter.
So he just linked each marble to a particle, an infinitely small point on which he set the boundary of influence to the radius of the marbles.
This type of simulation is much simpler. The primitive particles fall and the marbles just come along for the ride.
Holly: Wait, how did you just show that? The empty background and unrendered models?
C.D: Oh, I... found them...
C.D: Oh, I... found them... on Konstantin's Vimeo page.
Holly: We can get Adafruit optical RGB sensors for $8.99 a piece, and I think I have a concept for a sorting mechanism that uses vibrating pegs.
Although I will have to do some more research on resonance, there might be some issues there; but I can go get all the materials right now.
C.D: Wait a minute. I don't just look things up!
I deduce! There's much more to it. I mean even with everything I explained so far, you don't know exactly how he faked the actual color sorting, do you?
Holly: I guess not.
C.D: And you want to know, don't you?
Holly: Sure...
C.D: Well, small adjustments might affect a simulation every time it runs, making individual marbles fall differently.
Not something you want if you plan to render the scene multiple times, or have an exactly predictable end state for all the moving objects.
But unlike in the real world, CG physics can be baked.
Converted from on-the-fly calculations to keyframed animation, fixed permanently on every frame.
Once the path of each particle was fixed, all Konstantin had to do was go to the end of the shot, select each group of marbles, and give it a different tint.
In other words... Holly: He did it backwards.
C.D: No, he did it in rever- Yes, exactly!
See? It's all about thinking outside the box, working with the information you have to come up with the most likely scenario.
I might not have found the creator of the video, the simulation could have been flawless.
But I'd still spot something that gives away the video's fakeness. Some fundamental clue that makes the whole thing impossible.
Like for instance, the fact that before most of the marbles have fallen, they block the view through the board; allowing us to focus on the perfectly clear reflection in its flat, glossy surface.
A reflection, that despite facing us directly, shows no camera phone, or a person holding it.
Holly: D... My body is already a hologram. I have enough visual effects in my life. I want to go further, observe and figure out things about the universe that aren't known yet.
C.D: Well, I... Can't help with that...
Holly: I know.
But now I'm afraid it's time for me to go, kids. An accountant in Irkutsk is about to follow her weekly horoscope advice with disastrous results!
Holly: Oh, wow! Mu Cephei's core is finally about to collapse!
I've got to get to my observatory in the Elephant's Trunk Nebula to take real-time readings of the supernova!
C.D: Okay, that's a little cooler. I guess I'll see you around.
Holly: Yeah, I'll be back.
C.D: Maybe you can teach me some of this fancy stuff you're gonna learn, sometime.
Holly: I think this is the beginning of a beautiful friend zone.
C.D: Remember, love with your heart, Holly: Use your head for everything else.