Caustic lenses are really weird
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- เผยแพร่เมื่อ 15 ม.ค. 2023
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Sometimes called caustics or free form lenses, these objects use clever maths to move light around to make images.
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The sponsor is Henson. Get 100 free blades with your first safety razor: hensonshaving.com/stevemould use code stevemould
There is already a bot 😐
Thanks Steve mould I am a member
Alan Turing cut be looking fresh ngl
You should have done your head too for double the price.
Porn bots are out in force today. I really don't understand how they're supposed to work but I guess I'm not the target.
wait... did you use your beard as a progress bar?
the transition from the goofy shaving sequences to the horrible business model of printers to the sponsor was amazing
lol, I found it deeply disturbing for just a milisecond with a legit physical response and widening of the eyes 🤣
for real, I hope they payed extra for that effort!
Really well done. Got me to stick around for the sponsor spot.
You should have recorded the script in reverse to grow the beard back on
I listened to the first few minutes of the video, so glancing at the screen to see 1/3 of a beard was enough to make me rewatch from the beginning.
I love how you can clearly see Steve getting more and more giddy with this shaving bit as the video goes on.
I found it hard to focus on the actual content with the distraction of the shaving bit
😂
Yeah I'm sitting here just laughing and missing the whole point. Awesome video though. Home-made hologram sounds cool af.
I only noticed it halfway through and was very confused for a minutes XD
That smirk at the half shaved point
I cannot believe that I didn't see the changes in your facial hair until the half-way point. The strange feeling I got, once I realized it had been happening already and I'd been missing it, will be my main takeaway from this video. And the concept of caustic lenses will probably be floating around there somewhere too... but certainly not as palpably.
Same
I didn't notice it until 5:30 into the video. I was thinking "why does this guy have a beard like Kallus from Star Wars" only for him to turn right and I realized he *doesn't.*
The same
SAME ADHD CLAN @@eighdeekay7392
@@Pinoccappuccinox2
That. Is how you make a TH-cam video. Take notes people. This man. This man right here.
Loved how the shaving starts off subtly and gets progressively more. Way to go, all in for a sponsor. Hope they appreciate you.
I only noticed it first when half was already gone.
@ Same. That scene where only his cheek is shaved was completely missed.
All in? 😭😭😭 Shave a beard for 5 thousand dollars isn't all in 😂😂😂
@@ethanwasme4307 Depends on how much you value your facial hair.
@@ethanrandall3005 no, the amount of hair he had was of like 5-10 days of not shaving. Thats not all in no matter how you turn and twist it
Caustics are also one of the hardest problems in computer graphics, because light from anywhere in the scene might just end up on one of those bright lines, so you have to simulate a ton of light rays to get a noiseless image.
Which is why we cheat whenever we can get away with it. If you see an underwater render, chances are the caustics are not simulated, but instead they are just a animated texture overlaid on the geometry. In 99% of cases, it's good enough. In other renders, caustics are often turned off, unless they play a prominent role in the image, because they're not that noticeable. A drinking glass refracting onto the table is just a small bit of the image usually, for instance.
@@tylisirn this or prerendered emissive
I saw a machine learning solution to this problem not long ago. I don't mean showing caustics from an arbitrary surface, but generating the optimal surface for any given caustics. Now I can't find it anymore, but it was a bonus from their method of extracting/recreating scenes (lighting, shading etc) from an image.
I think they were at version 3, the name ended with the letter A, or was it a K? When is my neural implant ready?
Mitsuba 3 - differentiable rendering. I'll hold off on the implant until the first version after 2.0 that I can afford.
Intro video: watch?v=9Ja9buZx0Cs
I've heard it said that realtime caustics is the holy grail of computer graphics. I didn't have the background knowledge at the time, nor did I understand the context of the remark, so it stuck in my memory purely by virtue of the peculiarity of the words, but everything I've learned since then has reinforced it to the point that I'm not sure I'll ever see a realtime caustic render in my lifetime.
A1 video Mould. I’ve been subscribed since at least the 10th grade (im 25 now) and I can tell you that I’ve noticed how your videos have gone from purely informative to informative and genuinely entertaining. Feel like you’ve come into your own shoes in the TH-cam sphere. Can’t wait to see what you got cooking next man. This is one of the best educational channels on this site.
4:18 this is so cool, I would love to see something like a scaling medieval landscape with a castle or something but instead of it being thru the thin edge, carve it so if shine light thru it sideways you get a long flat artwork
You integrated the sponsorship so well and without interrupting the video that I watched the whole thing at the end out of curiosity and respect. Very well done!
Get the sponsor block extension
@@bubblecast Except in this case you would have to manually unskip the sponsor spot to get it.
@@qlum not with the extension
@@bubblecast depends on your settings, I guess
@@bubblecast 👎 I support good content creators by watching the segments. YT actually has metrics for how many ppl watch the segments which determines "reach" for the sponsor to know part of the value. It's not just straight up conversions. Just reaching someone has value cuz they might buy it later on without using Steve's sponsor code, maybe another code, after being influenced by multiple sponsorships. At least that's my guess. I don't actually know this from experience. But I've heard creators talk about these things.
1:11 - that's one of the most beautiful things that exists in my opinion. Since I was a kid I always were mesmerized by those lights under the water.
I tried scuba diving in a swimming pool. When I saw this pattern on the floor I was sold.
Also, 3:53
@@j.v.kelley6133 Agreed
"And the pool was filled with water out of sunlight,
And the lotos rose, quietly, quietly,
The surface glittered out of heart of light,
And they were behind us, reflected in the pool."
(T. S. Eliot, "Four Quartets")
Kostynha: OHHHHH! I was expecting you to say a beard disappearing.
Finally! I've been waiting for this follow-up!
Bro the gradually shaving your beard throughout the video melted my brain.
At EPFL (where the Alan Turing image comes from) there are a few of those acrylic panels under the library so that when sunlight shines on it, faces of famous people show up on the ceiling. Pretty impressive "resolution" too when the light shines just at the right angle
I scrolled the comments to see if someone mentioned the EPFL mirrors, and here you are.
They are under the Rolex Learning Center, I remember how amazed I was the first time I cycled under the structured and saw the reflexions above my head.
Cool! I'll have to go visit the EPFL now! Thanks for the info
The most impressive part is seeing the black areas, you'd just expect the non-lit sections to be the same as the loght passing through flat glass. Seeing that immense contrast is so cool!
The light that's focused in the bright parts has to come from somewhere.
@@stargazer7644 Obviously, I'm not denying the phenomena's existence. It's just that when seeing this kind of effect you'd expect it to look very low contrast, so it's against one's intuition.
What a cool idea for an episode and very well done. Very fascinating. Bravo
I know I probably will never NEED half of the knowledge I gain from this channel but I still look forward to it. I love learning about random things like this. Love this channel.
Fools collect money, the wise collect knowledge. Once gained, it's almost impossible to have it taken away from you. It's yours to keep virtually forever :)
Man.. The gags that Steve has for his first video of the new year always get me. Between his ballerina act last year and the disappearing beard gag this time, it makes me wonder if the family he visits during the holidays are all buttoned down people who don't respond to his humor, and he just has to let it all out afterward?
Thought I was going nuts at first lol
I can't help but notice how the reflections look just like a video waveform monitor when light reflects from them at a narrow angle, I think it is a good analogy for how they work
I'd have to agree with you on this one
+1 there, reminded me of the Captain Disillusion video "Color"
Video waveform monitor?
Is it tho?
I fail to see the connection. Could you elaborate?
smooth transition 🙂Also - the pattern made by those lenses when turning, reminded me of video waveform monitors.
Noticing half the beard gone at 3:49 really shocked me. Had to go back to make sure it wasn't gone from the beginning!
It's even more gone on 4:51
And it continues to happen throughout the video lol
Edit: it's connected to the sponsorship XD
@@ivanljujic4128 Each time he shows his face on camera, he has less beard. He did each shot sequentially, shaving between every shot. That's some dedication.
I absolutely love the creative approach to the ad read. We are so used to skipping over ads because they are just written by a company who is paying the creator to read a script. When a creator spends the extra time and effort to make the ad their own with a creative twist or spin on the ad read it really makes you want to watch the ad! Not because it’s an ad but because now it is content form the creator who you are there to watch in the first place.
The way you introduced your sponsor is so awesome!
visually encoded shaving transform is a nice touch and proves production & editing skills.
Love how you carried the sponsor all the way through for a reveal at the end. Just like the light shining through the glass reveals the lion. Brilliant!
I'm curious how they actually make these peices of glass.
I think they're acrylic? And if so, that's pretty easy, it's just a mold. Possibly an injection mold. Just a really fancy precise one, where they pay more attention than usual to the shrinkage and warping. The colorful one would be a little harder, but you could mold each of the pieces and then warm them together to fuse them.
@@OrigamiMarie
Wooow!!! You are so smart 🤓
Per their website, they can make them with almost any transparent material, but the easiest and most common are resin, glass, and crystal. Glass molding is not difficult, so when made with glass or crystal it would first be carved into a molding material, then the glass pressed into it, cooled, then tempered.
@@OrigamiMarie - Agree, and with glass, maybe with laser etching, but im not sure if can be polish after the etching and maintain the precision... if they do on glass, i would love to see how they do.
I bet a model of the finished piece could also be sls printed, then used to make the mold. Would definitely help with the precision required
Good job on the sponsorship spot! It did make me want to try a safety razor and I like well engineered items. I'd have been willing to pay £30 for the handle, but nearly £60 is too rich for me.
Thank you! Your videos always brighten my day. Then in top of that, I learn something new.
Half beard Steve is not real, it can't hurt you.
Half beard Steve: 3:48
I shaved half my beard (and the opposing side of my moustache) back in 1977 and it took until the evening for anyone to notice :)
there's also 5/6 beard steve at 1:38, 2/3 beard steve at 2:48, 1/3 beard steve at 4:50, and 1/6 beard steve at 6:55
The beard thing was a distraction so you wouldn't notice the gorilla lurking in the backround.
Single Mutton Chop Steve is his true final form
@@micahphilson I was waiting for the shave to continue over the top leaving him bald 🤣
That must've been so difficult to not laugh during the parts with the beard transitions.
Not just that. He had to make very sure the bits he already did were without mistakes. Once shaven, he can't go back to re-shoot an earlier section.
IIRC the optimal transport problem prompted a matematichian to make the first nomograph , wich is a printed analog computer composed of lines with numbers on and it's meant to be used with a string or a ruler ,
I reccomend checking them out because they are pretty awsome
That subtle smile, you know what you are doing with your beard. Bravo!
3:48 his beard is half gone but it’s all there in the shot before
Edit: it gets worse throughout the vid
This Is due to the sponsorship.
Thanks Captain Obvious.
Wait a damn second!
5 minutes into the video and I only just now notice that half his face is shaved?
Am I missing something?
XD
Btw great video so far.
Edit: okay the shaving is progressing as the video goes on... I am THOROUGHLY confused xD
I just noticed that too! It's disconcerting lol
@3:48
Ahh, that's better
@@metanevets91 yeah, turns out to be part of the sponsorship.
Very creative actually XD
@@idemanddonuts yaaa, and just a tad disappointing to a non sequitur lover...
Amazing explanations, thank you
The video is great as always, but man do i want one of those razors now, what a beauriful integration!
I'd love to learn about the deeper maths behind the optimum transport problem!
@@dav1dsm1th just like the proverbial fire - it's a good servant, but a bad master :) but it's never a friend
What if there is only a single math involved.................
Sounds more like 3 blue 1 brown video
Read en.wikipedia.org/wiki/Earth_mover%27s_distance
Nice shaving transition! I didn't notice until 6:00, lol.
An ad so well executed, I wish the usual sponsor blocks were more like this
Okay but that business card one from the beginning is genius-
Your 1/2 Five O' clock shadow hologram is very convincing! Super cool!
Great video!
you can start a fire using water as a lens! you just need pretty clear water and a lot of direct sunlight. there are a few different ways to make it work, but a ziplock bag full of clear water might be the easiest. i've also seen a regular water bottle do it with a lot of patience
You can certainly do it with ice.
Dewdrops have been known to start fires in hay.
@@stargazer7644 That is simply not true. Please don't trust anything you see on the internet.
Dew drops are way too small to do anything. They occur only in the morning when the sun is not as powerful either.
Dew can help catching hay on fire, but because of completely different reason and that's building up heat due to chemical reactions and microbial growth.
I vividly remember when a teacher's keyring at high school began to give off smoke. It was a sunny morning and there was a dead aquarium filled with water on the teacher's desk. The resulting lens near ignited plastic.
THANK YOU! FInally! some good explainer on controlling caustics. I really wish The Rayy would make a software that could make these virtually, or even better a depth pattern for cutiong out of metal
If you look up Matt Ferraro, he's done a great piece about these and has some Julia code that will export an .obj of an image of your choice.
Great video and yes Henson razors are awesome. Switched from cartridges a year ago and love the smooth shave and cost savings knowing that blades cost only $0.10. I usually get about 5-7 good clean shaves out of one.
Nice plug for the safety razors :)
I use one from the 50's, the plating is a bit worn but works just fine.
This is your best work so far Steve. It could even be the greatest TH-cam video ever made. Theme, explanation, advertising tease, all perfectly executed. You could also have mentioned that the razor blades involve no plastic waste, which was my main reason for buying a similar competitor that I won't mention for obvious reasons.
Man. This is possibly only time that a sponsorship in a TH-cam video has me sold on the spot.
Love the creativity of the sponsor implementation
So weird! I haven’t seen this particular video till now even though I’m subscribed. I didn’t notice the shaving thing till 4:50. I had to rewind and watch it from the beginning to see the progression. This just messed my brain up! How did I not notice? lol
Steve you're missing half your beard
Yes
6 minute late
You know what's funny till I saw your comment I hadn't noticed I was so focused on what he was saying.
I just realized it at 3:52 and had to check the comments
noticed minute 4.
"Once you know that you want 'hair' from your beard to go there..."
Loved the explanation as always! Steve is an amazing teacher who has mastered the art of explaining difficult concepts in a fun n engaging way.
You rock man!
Curious...and alarming! (and EXCELLENT tie-in for Henson!!! Well done!!!)
oo i've actually thought about this tech a few years back, how it could be used in lamps in a room to direct the light to more efficiently (and more prettily) illuminate the room
I always look forward to these video, thank you Steve!
I love when people cover new technologies such as this one that I didn't knew existed! Here is another recent technology that may interest people here : Cypris Materials has created polymer pigments, that while colorless when dry, turns to any color of the spectrum once applied as a paint. They work based on structural colors the same way as opals do. They have a few videos on TH-cam, they are worth watching!
I've seen a similar thing before concerning images having depth, the Kodak film 'Kodachrome' had layers which were said to improve the image - it was an extremely complex and therefore expensive developing process that was abandoned decades ago.
I absolutely stayed and watched the entire sponsor segment because I was super curious. Well played
You can also make that shape in coffee mugs by rotating a two circles of different diameters connected by a single point on each of their circumferences.
The mug version has an exact ratio of 2:1 for the smaller and larger rings respectively.
I can post images of several that I created a couple of years ago if you want to see some examples.
i was sitting by the pool today and i literally thought about the ripples that are caused and i thought about it and when i figured it out my first thought was "huh, could be a steve mould video"
love your videos man!
I have seen the designed mirror reflections, some are very antique religious artifacts. Very artistic treasures.
Great video.
I am working in a closely related field. If you do X-ray Nano-Imaging you have to solve the exact opposite you problem, you measure one of those smeared-out patterns where you can guess the coarse shape of the object, and your goal is to find the density of the object (your sample in the microscope) that has produced the pattern you observe. Mathematically it is almost identical. The more technical term for this is X-ray Inline Holography.
These are beautiful, thanks for shaving Steve!
What an ingenious lead in to the sponsorship. the whole video I'm like "okay... he's surreptitiously losing more and more facial hair every time it cuts back to him. wtf is going on?"
Hi Steve, what always mesmerises me is the steady transition between the visible image and the chaotic light. Isn't that - like with every lens - the steady fourier transition?🤯
I have been wondering since my bachelor if there's any usable information in that.
Ohhh, how awesome your channel is, I want this show on tv!
Interesting , Steve; it reminds me of the moiré fringe effect. I have always thought it would a fine idea if the bridges of motorways have the spacings of their grills altered so that, just at the right time, the moiré fringe spelt out something: 'Drive carefully', for example. The maths is well beyond me, but maybe the two ideas are related?
Tom Scott has a video on something like this th-cam.com/video/d99_h30swtM/w-d-xo.html
Probably best not to distract drivers with big signs, unless they're providing important information.
"How come you veered into the fast lane?"
"I was looking at the 'Drive Carefully' sign!"
🤦
There are moiré based road signs here in Europe that look like animated arrows, showing you upcoming turns
They have something like this for ship navigation apparently. See Tom Scott's video, "The moiré effect lights that guide ships home"
My 6yo, 8yo, and I love your videos!! Thanks so much for sharing fascinating science to all ages!!
Closest thing to this I've experienced is the Camera Obscure effect caused by my window shades. They're blackout style, but not true blackout, as the edges still let some light by. It's those edges that create the lens...
So when my mom is walking outside around the side of the house near my bedroom, I'll see her shadow get projected along the wall where that light is shining through. Or, the vehicle at it drives around the driveway.
Obviously, though, everything is upside down.... But it's still every bit recognizable. 😊
This definitely is related to the extended depth of field lenses for cataract patients and/or presbyopia correction....🤔
0:01 hi timed
@6:53 is that a pull back or is he just circumcised?
Imagine having this guy as your physics teacher
Well done integrating the sponsorship. Interestingly safety razors seem to be making a comeback on multiple fronts. As a decades long user of classic safety razors I applaud this an find it amusing at the same time. Feels a bit like being smug and saying „ah, finally… Took you long enough“. I was also fed up with the cost for the cartridges. Their only upside really is that you can usually put cartridges 😅into carry-on luggage if you happen to fly.
Great video, I’ve always been fascinated how you can manipulate projections of transparent 3d objects, seeing all the details magnified on a wall or something. Basic lenses lol.
No one noticed his beard disappearing.🤣🤣🤣
Like watching The Howling” but in reverse. Clever. Very clever! As always.
FWIW - I tried a ton of safety razors this spring and Henson is the best. Rad to see them sponsoring your video. It's so rare to see a product sponsor a content creator ... and the product is actually great! Go buy a Henson, do it now!
I always wanted to use things like this on that Glow In The Dark paper, to "store" the image
6:48 Everyone pauses to do a web search
That blurring is VERY generous.
@@michaelsteinbach it's a sensitive area
Safety razors are fantastic! Nice work on the sponsorship!
I love that you are holding back laughter in every cut where you're partially shaved.
Never seen such an immersive endorsement of a shaving razor .
I can confirm, safety razors are great. I bought one a few weeks ago for €20, you can get a pack of 100 blades for €0.10 a piece, and they actually shave _better_ than a conventional razor! Although it is also easier to cut yourself if you're not careful. This was actually the first time I cut my legs while shaving. Ouch. But you can also take them apart to get the hair out! So great!
Best sponsorship bit on youtube period. Awesome vid as always but as a lifelong electric shaver guy I'm genuinely tempted to get one of these just to support the business model
I normally like your videos, but the way you presented your sponsor was GOLD.
I 💯 support Henson already, but that just sold me all over again
Was waiting for this video, ever since I found the research done at EPFL I am fascinated - love to all the light enthusiasts out there! ✨
I also thought immediately of Differentiable Rendering. Do you know if this is the method Steve referred to or are there other ones?
@@theonetribble5867 Hi, CTO of Rayform here. It's not Differentiable Rendering, that is a more general method. This is a tailor-made solution that allows higher quality and high-contrast. You can see our Siggraph paper for more details.
I really thought a Fourier transform was going to be involved. I swear I learnt that at uni, maybe with lasers.
3:51 I like the Half beard cut, great new style!!!
I was once in the quality control department of a company that produced optical mark reading machines best known for test scoring. They sometimes used the Razor and Blades model. Sometimes we would give the customer the expensive machines for free if they bought enough forms to run through them. The forms are printed with special inks that are visible or invisible to the machines but not to humans.
What's wild is those Japanese "magic mirrors" that were crafted by hand hundreds of years ago that do something similar. They were created when Christianity was banned in Japan. It worked like a normal mirror but could also reflect an image of a cross in sunlight.
@@gregoryford2532 Oh! Thanks. I'll take a look.
Always enjoy Mould's playful approach to STEM.
Interesting video! I’d always thought they’d be similar to diffraction patterns, which are the Fourier transform of the diffraction grating. But it looks like the maths is much more complicated with caustics.
The mention of Optimal Transport made me realise that there must presumably be an infinite number of Suboptimal lenses that produce an identical image.
I wouldn’t call them suboptimal, because with light rays there is hardly any cost of deflecting them a bit more than necessary. The entire connection to transport theory is more a historic thing. Since the late 90s enough computing power is available to solve such problems in a more general way, with the Gerchberg-Saxton algorithm and its variants.
Since optimal lenses move the light the least they are also the most forgiving for placement issues, non-coplanar lense and screen, and placement at the wrong focal distance. Conversely suboptimal lenses would make the image harder to see until lens and screen are in the right position, which might actually be preferable.
Re: printers, a decade or so ago I looked into the numbers and saw it was legitimately cheaper to buy a brand new printer than to buy all new ink cartridges, and I did that a few times, giving away or selling the now inkless printer for extremely cheap. I've now got one that can use third party/refillable ink cartridges that are priced reasonably (there are plenty that will detect the non-brand-name cartridge and refuse to operate!) and it's a good printer that doesn't hassle me, too :) Still hate printers, though.
Laser printers are still probably a better purchase for those people who don't need photograph-quality image prints. Toner doesn't dry out the way inkjet ink does, and it comes in bigger amounts, so it's changed far less often, which means they also don't do the razor-and-blade pricing model.
"cheaper to buy a brand new printer than to buy all new ink cartridges"
and they made the printer come with only 1/3rd filled cartridges. And now the "refillable" printers often have design like a non-replaceable cleaning-ink-reservoir that simply locks up the printer after a certain number of uses -.-
Consumer-printers are still a scam. I switched to simply using a copy-shop - printing there is simply cheaper than having a printer at home (kinda insane actually). And as it is a university copyshop you can just send the documents via mail or through a share and get them at 2 in the morning.
This is not true and hasn’t been for a while. New printers come with an incredibly small fraction of a full ink cartridge ever since the whole “just buy a new printer each time” idea became very popular in the 2000s. You didn’t need to do the math, literally everyone was talking about it and doing it.
5:49 How do you do that? Do you cover up one side so it gets no light to prevent the hairs from growing?
He cut that side and left the other side alone
love the editing, that beard just was gone and didn't notice that you removed some before half was gone
I had a custom made dog tag with a picture on it that use to reflect the image perfectly onto various surfaces was the coolest ever
I didn't notice the beard until 4:55.
These are beautiful, thanks for sharing Steve!
I love crazy stuff like this!
🎯 Key Takeaways for quick navigation:
00:00 🌞 Caustic lenses can produce recognizable images by manipulating lens shapes.
01:03 💧 The patterns caused by undulations in transparent materials are related to how lenses work, focusing light rays to create bright lines called caustics.
03:00 🔍 Shaping lenses to redistribute light optimally is an area of mathematics known as optimal transport, akin to sculpting sand with minimal movement.
04:27 🌐 Power diagrams represent the distribution of light, and adjusting them influences the brightness and darkness of regions in an image.
05:53 🖥️ Computer scientists like Mark Pauly have contributed to understanding and implementing the curvature of lenses to create specific images.
06:51 🌈 The transition from familiar light patterns to recognizable images in these lenses creates visually engaging moments.
08:16 💼 The video sponsor, Henson, makes well-engineered safety razors, providing an alternative to the expensive "razor and blades" business model.
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