The indefatigable Ke-Sen Huang has collected links for papers at both HPG 2023 and EGSR 2023:
HPG at https://www.realtimerendering.com/kesen/hpg2023Papers.htm – includes direct links to recordings
EGSR at https://www.realtimerendering.com/kesen/egsr2023Papers.htm

I’ve heard both were well-attended this year (and I’m sad I missed them – it didn’t time out), with about 150 attendees at EGSR, something of a record.

Elena Garces and I are co-chairing papers for EGSR 2024, so keep up the great work and interest, all! I would expect the papers deadline to be around April, similar to this year’s Call for Papers deadlines.

It turns out that, at the bottom right of the project page I pointed to in my previous post, there’s a link to a Windows implementation of their system. I hadn’t noticed that; thanks to James Hung-Kuo Chu, first author of the work, for the tip-off. He has a nice example of a colored QR code on his web page.

The Windows program works! Set a URL or text to search, upload a picture, ask for a QR code.

Here’s an example. Blur your eyes to help you figure out what well-known computer graphics image it represents. I find you’ll want to have the QR code be not very large in your camera’s view for it to be detected as one.

A smaller one, of me. Again, blur eyes. When changing the size it’s likely best (?) to “pixel resize” (sample and hold, etc.), not resampling.

Addendum: James Hung-Kuo Chu, the first author on the paper, noted that using the “Apply contrast enhancement” can give a better result. Here’s one with that:

Addendum 5/28/2023: I just noticed this article, pointing to another QR image generator. The color one’s more fun, IMO, but I wanted to scribble down where this other tool is.
And addendum 6/7/2023: this cool QR maker guided by Stable Diffusion (thanks to Andrew Glassner for pointing it out). Actual creator tool here.
Also, 12/14/2023: a research topic is to make a 2D barcode that tries to be more aesthetically pleasing than a QR code. Me, I think that ship has sailed – adopting a new barcode format seems unlikely – but, interesting topic and a view of “what might have been.”

In talking with Niloy Mitra, I noticed he had a cool QR code on his page. I asked him about it, he pointed me to this decade-old work he coauthored. Searching a bit more, I found a cute web browser version for making your own. It’s a bit flaky, in that a lot of the images I tossed in look really bad half-toned. Maybe if I had a clue what the options were it’d come out better. But, with one it worked pretty well! I just put in the URL I want the code to lead to.

Addendum: but wait, there’s more! Another generator, from the author, that also permits color output. See my next post.

Like it says. Hotel reservations for SIGGRAPH 2023 are now open: https://s2023.siggraph.org/travel-accommodations/ – from what I see, you can cancel cost-free up to the end of July. So, if there’s any chance you’ll go, lock it in now. To save you a click, SIGGRAPH is August 6-10 in Los Angeles.

It’s SIGGRAPH’s 50th year, so I expect a fair bit of retrospective stuff. In fact, the Electronic Theater is accepting such material until May 1st, so if you’re of an age, dust off those VCR tapes for submission.

I3D 2023 is back to being in-person, first time since 2019. May 3-5, hosted at the Unity office in Bellevue, WA, USA.

The last in-person I3D was in 2019. I helped chair the conference on-line in 2020 and 2021, and 2022 was also remote. We survived, good work got published, but half the joy of any conference is meeting with people, new and old.

The nice thing about on-line conferences is that they cost just about nothing. Which means all the money we raised from sponsors in 2019 and later is available for this year’s conference. Almost all sponsors generously rolled over their donations each year for the time when the conference would again be in person. That time is now! I don’t know, but suspect there should be a fair number of new people attending this year, as there was money in 2020 (before COVID hit) for student travel grants and outreach programs.

Please spread the word and retweet.

Today’s theme is interactive mash-ups and remixes:

• Play Lunar Lander in the Windows copy dialog when you’re copying lots of files from one place to another.
• Live the dream: you can be an unpaid K-Mart associate in VR. Closed for Christmas, but now back and chock-full of post-holiday White Sale and bluelight specials, along with everyday deals, like buying six cassette tapes and getting the seventh free. One explanation here.
• Put “Doom running on” in Google and you’ll see some fun autocompletes. The pregnancy test one’s a hoax. But running Doom in Windows Notepad seems legit.
• There’s candy bar Doom, which is frankly pretty dumb but for the slogan, “do not eat if it’s Turing complete.”
• You might have missed how rats have been trained to play Doom II. They don’t seem to be very good at it, though, but are kinda cute running on the ball.
• Sadly, Doom running on an IKEA TRÅDFRI GU10 RGB lamp controller has only left a trace after a takedown. But, through the magic of archive.org, there’s more that can be unearthed, including the code (but not the video, sadly).
• Katamari Hack. The items above are all pretty involved to do yourself. This last one’s a little fussy to get going, but just 30 seconds work. On that page is a bit of Javascript at the top, in a box. Copy it. Go to some web page, such as this one or this, on Chrome (may work on others) and hit F12 (on the PC; on a Mac it’s command-option-i). In the debug area that appears, choose the Console tab, paste the Javascript, hit return. A dialog should appear in the web page. Hit “Start!” and then right-click hold to roll the ball around. Have fun! Note that browsers and https security has evolved such that this little hack won’t work on many pages, so enjoy it on the few that do.

Let’s focus on colors. We’re in, we’re out, it’s quick, unlike yesterday’s post:

• Jos Stam told me about the color named Isabelline. The story’s probably apocryphal, but fun. This one’s now in my neurons along with chartreuse and puce. As well as the trademarked pink (I found the full rundown here).
• Is it fuschia or fuchsia? I finally forced myself to learn the right one a few years back.
• Car paint in real life: it’s complicated.
• Harvard’s art museum has a collection of pigment for colors. It’s off limits to most people, in part because some contain dangerous chemicals. Someone just tipped me off that there are video tours, however. Here are three: short, medium, longer.
• Wikipedia has a crazy long list of colors, divided into parts. Here’s G-M. I like the duh text there, “Colors are an important part of visual arts, fashion, interior design, and many other fields and disciplines.” Proof that Wikipedia is meant for aliens who have never visited Earth before.
• If you just can’t get enough about colors, consider getting the book The Secret Lives of Color. Some you’ll know, some’s obscure knowledge (when did red, yellow, and blue become the primaries?), some’s more obscure knowledge (the long list of colors, each with a story, making up the bulk of the book). It’s relatively cheap and, well, colorful – nicely produced.
• Need more colors? AI’s got your back. So so many great names here, I can’t even pick out just one. Just a few shown below.

Time to catch up with too many links collected this past year. Today’s theme: interactive web pages. Plus, bonus nostalgia!

• Karl Sims’ Reaction Diffusion Tool. Play with the sliders, or just hit the Example button (up to 20 times) for some fantastic presets. If you’re old enough or nerdy enough, you’ll know Karl Sims from his SIGGRAPH papers in the early ’90s, such as this one. You’ll also then likely know of the two reaction-diffusion SIGGRAPH papers from 1991 (1, 2), based on Alan Turing’s paper in 1952. Now together, in one lovely web app.
• Recursive Game of Life. Use the mouse scroll to zoom in and out, left-drag to pan. In high school I used to hand-evolve Life patterns on graph paper, then later print out generations on green and white paper using the school’s administrative computer. This infinite recursive Life evolver would have fried my brain back then. Look closely and admire how cells get filled using glider guns and there’s some message passing between cells done with glider streams. (Follow-up: secrets revealed here. Thanks to Eran Guendelman for the tipoff.)
• Omio.io works. The recursive game of Life is the first one here, followed by many others. I’ve looked at only about half of these so far, as it’s like a box of delicious chocolates. You want to savor but one at a time, though maybe nibbling just one more would be OK… And each is a little puzzle: what’s this about? how do I interact? A few are just links to projects – consider these strawberry creams or coconut clusters from an interactivity standpoint, but they’re still interesting. There are earlier works (as GIFs) from the creator, who I now am most definitely following on Twitter (and thanks to Jacco Bikker for the tip-off).
• The Origami Simulator is misnamed, in that it simulates all sorts of papercraft patterns. Poke around under the Examples menu to see what I mean. While unlikely to help you make any of these, it’s fun to look at and drag the Fold Percent slider. For me, instant nostalgia: I attended the OrigaMIT convention last month, mostly admiring the amazing creations. Some pics, plus a NeRF I made of one display, and another NeRF.
• I mentioned Townscaper in the browser last year in a blog post around this time of year. It’s a lovely way to build a picturesque town, but what about destroying one? Behold Toy City. It takes a bit to load and initialize; you’re ready when the red ball (i.e., you) appears. Then WASD, arrow keys, and space bar your way to cute toppling. This was made with “Spline,” described as “A friendly 3d multiplayer design tool that runs in the browser.” I haven’t explored this app further yet…
• If you desperately need to visit another super-cute environment, see Choo-Choo World. Me, I can barely make a track loop, but it’s still tooth-achingly pretty. This one’s produced by Lusion, which is either a firm, “the place where all real-time magic begins,” or a dark entity from beyond the abyss, judging from the music that plays when you visit and then go to any other page of theirs (“contact” is great). In reality, the pages there are fun and point to a bunch of other projects to check out. It’s “interesting” to read about interactive story books (like this one) while listening to their music of doom.
• But, really, what we most need is a web page that finds our pointer. Done.

What’s really happening in a single cell in Life:

I asked Andrew Glassner if he had the original paper issues of the Ray Tracing News available. He replied, “About an hour ago I entered the vault, filled with nitrogen to prevent decay, put on the fiber-free white gloves, and was allowed to view the original manuscripts.” In other words, he found them in some box (I suspect I have them in some different box, too, somewhere…). He kindly scanned all four and they’re now available as PDFs, hosted here.

Andrew started this informal journal for us ray tracing researchers immediately after SIGGRAPH 1987, where he had organized the first “ray-tracing roundtable.” It was no mean feat to gather us together, check the email list at the end of the first issue. Tip: I’m no longer at hpfcla!hpfcrs!eye!erich@hplabs.HP.COM. Delivery was like the Pony Express back then.

Having these (virtually) in hand makes the Ray Tracing News collection online complete, sort of like catching all the Pokémon. It’s nice to have these publications available on the web now. I enjoy seeing ideas such as Jim Arvo’s simulated annealing and Paul Heckbert’s minimal ray tracer where they first appeared.

And, the issues have filler cartoons, made by Andrew – these follow. Hey, I enjoyed them. Ray tracing is not a rich vein of comedy gold; there isn’t exactly an abundance of comics on the subject (I know of this, this, and this one, at most – xkcd and SMBC, step up your game. Well, SMBC at least had this, and xkcd this).

We finally, a mere 30-odd years later, have tracing tablets (if you view some Shadertoys on an iPad).

I just finished the book Euler’s Gem. Chapter 7 starts off with this astounding statement:

On November 14, 1750, the newspaper headlines should have read “Mathematician discovers edge of polyhedron!”
On that day Euler wrote from Berlin to his friend Christian Goldbach in St. Petersburg. In a phrase seemingly devoid of interesting mathematics, Euler described “the junctures where two faces come together along their sides, which, for lack of an accepted term, I call ‘edges.'”

The book uses as a focus Euler’s polyhedron formula, V-E+F = 2. I agree with the author that this thing should be taught in grade schools, it’s so simple and beautiful and visual. I also agree that it’s amazing the ancient Greeks or anyone before Euler didn’t figure this out (well, maybe Descartes did – read the book, p. 84, or see here).

He continues some pages later:

Amazingly, until he gave them a name, no one had explicitly referred to the edges of a polyhedron. Euler, writing in Latin, used the word acies to mean edge. In “everyday Latin” acies is use for the sharp edge of a weapon, a beam of light, or an army lined up for battle. Giving a name to this obvious feature may seem to be a trivial point, but it is not. It was a crucial recognition that the 1-dimensional edge of a polyhedron is an essential concept.

Even though Euler came up with the formula (though was not able to prove it – that came later), the next mind-blowing thing was reading that he didn’t call vertices vertices, but rather:

Euler referred to a vertex of a polyhedron as an angulus solidus, or solid angle.

In 1794 – 44 years after edges – the mathematician Legendre renamed them:

We often use the word angle, in common discourse, to designate the point situated at its vertex; this expression is faulty. It would be more clear and more exact to denote by a particular name, as that of vertices, the points situated at the vertices of the angles of a polygon, or of a polyhedron.

Me, I found this passage a little confusing and circular, “the points at the vertices of the angles of a polygon.” Sounds like “vertices” existed as a term before then? Anyway, the word wasn’t applied as a name for these points until then. If someone has access to an Oxford English Dictionary, speak up!

Addendum: Erik Demaine kindly sent on the OED’s “vertex” entry. It appears “vertex” (Latin for “whirl,” related to “vortex”) was first used for geometry back in 1570 by J. Dee in H. Billingsley’s translation of Euclid’s Elements Geom. “From the vertex, to the Circumference of the base of the Cone.” From this and the other three entries through 1672, “vertex” seems to get used as meaning the tip of a pyramid. (This is further backed up by this entry in Entymonline). In 1715 the term is then used in “Two half Parabolas’s [sic] whose Vertex’s are C c.” Not sure what that means – parabolas have vertices? Maybe he means the foci? (Update: David Richeson, author of Euler’s Gem, and Ari Blenkhorn both wrote and noted the “vertex of a parabola” is the point where the parabola intersects its axis of symmetry. David also was a good sport about my comments later in this post, noting his mother didn’t finish it. Ari says in class she illustrates how you get each of the conic sections from a cone by slicing up ice-cream cones, dipping the cut edges in chocolate syrup, and using them to print the shapes. Me, I learned a new term, “latus rectum” – literally, “right side.”)

It’s not until 1840 that D. Lardner says “These lines are called the side of the angle, and the point C where the sides unite, is called its vertex.” So, I think I buy Euler’s Gem‘s explanation: Euler called the corners of a polyhedron “solid angles” and Legendre renamed them to a term already used for points in other contexts, “vertices.” OK, I think we’ve beat that to death…

So, that’s it: “edges” will be 272 years old as of next Monday (let’s have a party), and “vertices” as we know them are only 228 years old.

By the way, I thought the book Euler’s Gem was pretty good. Lots of math history and some nice proofs along the way. The proofs sometime (for me) need a bit of pencil and paper to fully understand, which I appreciate – they’re not utterly dumbed down. However, I found I lost my mojo around chapter 17 of 23. The author tries to quickly bring the reader up to the present day about modern topology. More and more terms and concepts are introduced and quickly became word salad for me. But I hope I go back to these last chapters someday, with notebook and pencil in hand – they look rewarding. Or if there’s another topology book that’s readable by non-mathematicians, let me know. I’ve already read The Shape of Space, though the first edition, decades ago, so maybe I should (re-)read the newest edition.

On the strength of the author’s writing I bought his new book, Tales of Impossibility, which I plan to start soon. I found out about Euler’s Gems through a book by another author, called Shape. Also pretty good, more a collection of articles that in some way relate to geometry. His earlier book, a NY Times bestseller, is also a fairly nice collection of math-related articles. I’d give them each 4 out of 5 stars – a few uneven bits, but definitely worth my while. They’re no Humble Pi, which is nothing deep but I just love; all these books have something to offer.

Oh, and while I’m here, if you did read and like Humble Pi, or even if you didn’t, my summer walking-around-town podcast of choice was A Podcast of Unnecessary Detail, where Matt Parker is a third of the team. Silly stuff, maybe educational. I hope they make more soon.

Bonus test: if you feel like you’re on top of Euler’s polyhedral formula, go check out question one (from a 2003 lecture, “Subtle Tools“), and you might enjoy the rest of the test, too.

Oh, and the 272nd birthday of the term “edge” was celebrated with this virtual cake.