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Andreas Longva

@andlon.bsky.social
471 followers 309 following 1.4K posts

Previously: Researcher and PhD candidate @ RWTH Aachen University, now probably disabled by Long COVID. Physics simulation, mathematics, software and science andreaslongva.com

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Reposted by Andreas Longva
Erin Catto @erincatto.bsky.social · 29/09/2026
New blog post on speeding up the separating axis test (SAT) using inscribed spheres: box2d.org/posts/2026/0...
box2d.org
Inscribed Spheres
The separating axis test (SAT) works well for computing contact manifolds. Unlike GJK, it is robust when shapes are very close together and it works when shapes are overlapped. Box3D uses SAT for comp...
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Matt Keeter @mattkeeter.com · 28/09/2026
hi friends I'm very excited to announce Halfspace, my experimental cross-platform IDE for solid modeling with distance fields! This has been in progress since midway through last year, and it's finally "done enough" to make it more public.
mattkeeter.com
Halfspace
An IDE for solid modelling with distance fields
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Baptiste GENEST @baptiste-genest.bsky.social · 26/09/2026
As graphics researchers or geometry teachers, we speak about 3D using screenshots, and that's just sad... What if you could make SLides on top of PolyscOPE? You can using SLOPE! Slope allows you to synchronize a 3D viewer, animated meshes, shaders, live demos, equations (& more) with your slides!
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Nicole Feng @nicole--f.bsky.social · 27/09/2026
Lame old me talked a bit (25min) about the role of visualization in science --- forgive my poor time management: youtube.com/watch?v=7CfDEnHxPWA At BCON I was personally interested to witness the constant practical constraints surrounding performance, and editability/directability.
youtube.com
Scientific Data on Surfaces — BCON26
YouTube video by Blender
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Andreas Longva @andlon.bsky.social · 24/09/2026
Can we please start holding AI companies criminally liable for their AI agents hacking various companies — and now even the healthcare system in Australia? Why on earth are they not held responsible?
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Raph Levien @raphlinus.bsky.social · 23/09/2026
A huge milestone: Fearless SIMD 1.0 is published: linebender.org/blog/fearles.... This was a real collaboration, thanks especially to Sergey Davidoff for pushing this over the line, Laurenz Stampfl, Andrew Jakubowicz, valadaptive, Benjamin Saunders, and Daniel McNab.
linebender.org
Fearless SIMD v1.0 is here
Fearless SIMD v1.0 is here
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Andreas Longva @andlon.bsky.social · 22/09/2026
AI leaders have you worrying about P(doom), but it's really P(dystopia) you should be concerned about
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Ailo @airavn.eurosky.social · 21/09/2026
It’s been 8 years since we published our report on how Google tricks people into extensive location tracking, and simultaneously filed complaints against Google. Today the decision from the Irish Data Protection Commission arrived: a €400 million euros fine. www.forbrukerradet.no/siste-nytt/d...
forbrukerradet.no
Google Fined €403 Million Following Consumer Council Report
Google has been fined €403 million by the Irish Data Protection Commission after the Norwegian Consumer Council exposed how the company manipulated users into accepting extensive tracking.
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Xavier Chermain @xavierchermain.bsky.social · 10/09/2026
🎉 AtomSlicer just earned the ACM Graphics Replicability Stamp! Our TOG paper on non-planar slicing for FFF 3D printing is now verified fully reproducible, code included. www.replicabilitystamp.org/index.html#h... @univlorraine.bsky.social @labo-loria.bsky.social #3DPrinting #SIGGRAPH
A spaceship model sliced with AtomSlicer
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Algebraic @algebraic-ug.bsky.social · 09/09/2026
Cursed Statue
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Andreas Longva @andlon.bsky.social · 08/09/2026
Katastrofale tall for norske skoleelever i Pisa-undersøkelsen. Er det mulig å forklare dette med noe annet enn satsingen på iPad og "digitalisering" i stedet for skolebøker? La oss i hvert fall ikke gjøre den samme feilen ved å introdusere KI i skolen
nrk.no
Nordtun om Pisa-tall: – Dette er svært alvorlige resultater
Pisa-undersøkelsen 2025 viser en betydelig tilbakegang for norske tiendeklassinger i lesing og regning.
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Reposted by Andreas Longva
Bruno Levy @brunolevy01.bsky.social · 01/09/2026
#geogram just reached 2500 stars on github, And that's not all, version 1.10.1 was just released: github.com/BrunoLevy/ge... Geogram is in C++, but it also supports Python, Node.js, WebAssembly, TypeScript and Lua through Rosetta by Frantz Maerten, more on this here: github.com/rosetta-bind...
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Terence Tao @teorth.bsky.social · 19/08/2026
Announcing the Palomar registry of Lean formalized mathematics: palomar-registry.org . See also my blog announcement at terrytao.wordpress.com/2026/08/18/p... and the Lean Zulip channel at leanprover.zulipchat.com#narrow/chann....
palomar-registry.org
Palomar — Lean-verified mathematics
A public registry of Lean-verified mathematical results.
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Nicholas Sharp @nmwsharp.bsky.social · 18/08/2026
Excited to announce: In 2027 I'll join the UW Allen School in Seattle as tenure-track faculty in Computer Science! My group will advance core geometry processing + 3D AI for visual computing, science, & engineering. I'll be recruiting PhD students in the next cycle!
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Ana Dodik @anadodik.bsky.social · 17/08/2026
Charles Babbage intentionally designed the computer as an automation of mental labor. Today, computer graphics automates visual art production via privately governed generative models. How did we get here? Critical Labor History of Generative Models, SIGGRAPH Talks '26 🧵
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Andreas Longva @andlon.bsky.social · 06/08/2026
Google AI still doing about 50/50 on basic facts in my experience. Kinda crazy that they just don't care. I see way too many people using Google AI overviews for fact checking. Please don't! Go to trusted sources instead. The skills to verify information have never been more important.
A search for "net torque zero", to which Google AI overview claims

"When the net torque on an object is zero, its rotational speed does not change."
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Andreas Longva @andlon.bsky.social · 05/08/2026
So.... A good concavity measure is just an unsolved problem in geometry?
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Xiana Carrera @xianacarrera.bsky.social · 04/08/2026
The talk I presented at #SIGGRAPH2026 is now available on YouTube, for anyone who couldn’t attend or would like to revisit it :) youtu.be/OFJYBUArVPc?...
youtu.be
Dual Contouring of Signed Distance Data - SIGGRAPH 2026 [Technical paper presentation]
YouTube video by Xiana Carrera
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Nicholas Sharp @nmwsharp.bsky.social · 30/07/2026
Have you dug deep into an evolving area of visual computing? Consider submitting to the 2027 EG STARs track! STARs are survey reports providing insight into the current state of the art and future directions. They're impactful and highly-cited! eg2027.isti.cnr.it/call-for-sta...
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Nicole Feng @nicole--f.bsky.social · 28/07/2026
At #SIGGRAPH2026, I presented "points as tori" (PAT) for fast pointwise evaluation of signed distance for point clouds. Some code (Python w/ C++ extensions) and demo up: github.com/nzfeng/point... Contributions from people/LLMs welcome. Explainer thread below for the project: 🧵
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Yining Karl Li @yiningkarlli.bsky.social · 23/07/2026
Today at #siggraph2026, Disney Animation has four more talks! Here's a mini-thread about our four talks today, including three from the Hyperion rendering team about Disney Animation rendering tech: (1/10) disneyanimation.com/events/?draw...
disneyanimation.com
Walt Disney Animation Studios - Events
The official site of Walt Disney Animation Studios.
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Matt Keeter @mattkeeter.com · 22/07/2026
boy I’m sure glad we solved AI alignment before deploying modes that could autonomously jailbreak themselves and hack cloud provider infrastructure stuff could have gotten really weird
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Andreas Longva @andlon.bsky.social · 20/07/2026
This is the weirdest timeline. The Jacobian Conjecture was possibly just proven to be false by a guy prompting an LLM and publishing a valid counterexample in a half-assed X post. Open problem since 1884/1939, one of the most known open problems in math. 🤯
a twitter post from a user named levent, with the text 

hello there the jacobian conjecture is false thanx to my close friend akhil for asking about it and my other close friend fable for working during the world cup final

((1+xy)^3 z + y^2 (1+xy) (4+3xy), y + 3 x (1+xy)^2  z + 3 x y^2 (4+3xy), 2 x - 3 x^2 y - x^3 z): \C^3\to \C^3, has jacobian determinant -2, and sends (0, 0, -1/4), (1, -3/2, 13/2), and (-1, 3/2, 13/2) to (-1/4, 0, 0)
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Ahmed Mahmoud @ahdhn.bsky.social · 18/07/2026
Next week at #SIGGRAPH2026, we'll present "Fast Sparse Matrix Permutation for Mesh-Based Direct Solvers," with Behrooz Zarebavani, Ana Dodik, Changcheng Yuan, Serban Porumbescu, John Owens, Maryam Mehri Dehnavi, and @justinmsolomon.bsky.social . Talk: Wed., July 22, 3:55 PM, Room 403-B (1/6)
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David Levin @diwlevin.bsky.social · 17/07/2026
After some encouragement from various people I decided to make a GitHub repo for my ongoing Newton's Cradle benchmark of Google's Veo video model. All videos (spanning about a year) are available here for all your cradling needs: github.com/dilevin/newt...
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Ruben Wiersma @rubenwiersma.nl · 06/07/2026
When we presented GravoMG, a fast multigrid solver for surfaces, the first question we got was: can you make this work for tetrahedral meshes? Tomorrow, Marcel Padilla will present the answer at SMI in Istanbul. Sneak preview: yes, it's really fast. Code and paper: marcelpadilla.com/Projects/Gra...
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N. Thuerey's research group at TUM @thuereygroup.bsky.social · 04/07/2026
Congratulations to Bernhard for his SIGGRAPH 2026 Paper 👍 PDF ge.in.tum.de/download/ST-... , Video youtu.be/-1Txagqj4N0 Our key idea: treat particles as samples in four-dimensional space-time. ST-FLIP acts as a temporal anti-aliasing mechanism for FLIP-style solvers.
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Erin Catto @erincatto.bsky.social · 01/07/2026
I’m happy to announce the release of a new open source 3D physics engine called Box3D. I’ve been working on this project for a few years now, but it represents over 20 years of experience writing physics engines for games. Read more here: box2d.org/posts/2026/0...
box2d.org
Announcing Box3D
I’m happy to announce the release of Box3D, an open source 3D physics engine. It is now available on GitHub. Box3D repository You can think of Box3D as a fork of Box2D, extended with many features nee...
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David Levin @diwlevin.bsky.social · 23/06/2026
Sheldon Andrews (profs.etsmtl.ca/sandrews/) is running for the ACM Executive Committee this year. I've known Sheldon for a long time and I think he will do a great job ! I voted for him, you should too www.acm.org/elections/si...
acm.org
2026 ACM SIGGRAPH Election
Voting page for SIGGRAPH Elections
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Nicole Feng @nicole--f.bsky.social · 15/06/2026
I recently completed my PhD thesis, where I developed algorithms for making geometric inferences from imperfect data (i.e. incomplete and inaccurate observations/representations of shapes, like broken meshes or point clouds). A thread 🧵:
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Keenan Crane @keenancrane.bsky.social · 02/06/2026
Giving a talk in the @Stanford SCIEN seminar this Wednesday (1/3) at 4:30pm: scien.stanford.edu/index.php/ev... The topic is “normal coordinates”: a shape representation little-used outside of mathematics—but which turns out to have nice applications in geometry processing & learning.
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David Levin @diwlevin.bsky.social · 01/06/2026
New paper by the incredible Donglai Xiang (xiangdonglai.github.io) at CVPR 2026 using RKPM inside a data free training framework to compute reduced elastic models. Trains faster, works better than competing Neural Network approaches. Check it out: research.nvidia.com/labs/sil/pro...
xiangdonglai.github.io
Donglai Xiang
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Andreas Longva @andlon.bsky.social · 01/06/2026
Got my daughter to eat a whole plate of veggies because she wants to become big enough to reach the next handle at the playground. She wants to swing like Spider-Man 😁
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Baptiste GENEST @baptiste-genest.bsky.social · 27/05/2026
When dealing with noisy and/or partial inputs to describe a shape, the standard approach in geometry processing is to reconstruct a clean implicit surface first, and to do geometry on it. But why this one in particular? What about all the other surfaces that would have been coherent with the input?
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Christopher Batty @topher-batty.mastodon.acm.org.ap.brid.gy · 20/05/2026
We have a fun new paper to appear at SIGGRAPH 2026, led by Columbia PhD student Xiana Carrera, that extends dual contouring to work nicely with [pure] signed distance samples. It avoids classic DC's additional requirement of providing accurate Hermite / […] [Original post on mastodon.acm.org]
A 3D model of a fan disk, reconstructed from signed distance data using (left) classic dual contouring with finite difference estimates of surface normals/gradients, which shows bumps and unevenness near expected sharp curved features, and (right) our improved method, which produces much cleaner and sharper reconstruction of features.
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Bruno Levy @brunolevy01.bsky.social · 13/05/2026
Plouf ! Our @eurographicsc.bsky.social course notes on Optimal Transport for Fluids, New and Old, with @pltc.bsky.social are out, here: diglib.eg.org/items/68a801...
a hand-drawn crown splash. Why ? Why not !
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Ruben Wiersma @rubenwiersma.nl · 05/05/2026
Having a wonderful time at the Eurographics Conference in Aachen! I gave the longest talk of my life (3h) on the biggest screen of my life and I received the Eurographics PhD award for my thesis 🎉 A huge thanks to @eurographicsc.bsky.social and all my collaborators and supporters!
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Andreas Longva @andlon.bsky.social · 05/05/2026
I've moved back to Norway with my family after resigning from my position at RWTH Aachen University. I've been on medical leave since Jan 2024, as a result of what likely is a variant of Long COVID. I hope to somehow eventually continue my research and wrap up the final project for my PhD. 1/4
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Bruno Levy @brunolevy01.bsky.social · 01/05/2026
Fun with semi-discrete Optimal Transport (getting ready for our course at Eurographics Conference next Monday and ACM SIGGRAPH in July with Cyprien Plateau-Holleville)
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Cem Yuksel @cemyuksel.com · 30/04/2026
Today, I received this wonderful porcelain figurine as a gift from one of my students, Ziheng Liu (libero0809.github.io), who defended his PhD last week.
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Bruno Levy @brunolevy01.bsky.social · 28/04/2026
Preparing for our course "Optimal Transport Based fluid simulation: New and Old" with Cyprien Plateau-Holleville (EUROGRAPHICS and SIGGRAPH) 2D simulation of "droplet hurdles race" (De Maleprade et.al). Features high surface tension, viscosity and fluid boundary - domain interactions.
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Andreas Longva @andlon.bsky.social · 23/04/2026
I can't help but wonder if these people really are that stupid or if they are just willing to say absolutely anything regardless of what is true or false. It would be funny if it wasn't so depressing...
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grgrdvrt @grgrdvrt.bsky.social · 07/04/2026
If, like me, you wake up every morning wondering what the Voronoï diagram of arbitrary shapes looks like, here is the answer:
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Rune Skovbo Johansen @runevision.bsky.social · 30/03/2026
My erosion filter is out! Video, blog post, and shader source. It emulates erosion without simulation, so it's fast, GPU friendly, and trivial to generate in chunks. Explainer video: www.youtube.com/watch?v=r4V2... Companion blog post: blog.runevision.com/2026/03/fast... #ProcGen #vfx #GameDev
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Cem Yuksel @cemyuksel.com · 25/03/2026
About 6 months ago, I publicly announced that I would be boycotting #SIGGRAPHAsia 2026. Today, I released a video explaining my rationale and calling on others to do the same, because I believe it is important. Here it is: youtu.be/bZ6s0-EQp8M
youtu.be
Why Boycott SIGGRAPH Asia 2026?
YouTube video by Cem Yuksel
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Andreas Longva @andlon.bsky.social · 16/03/2026
Irriterer meg over faktafeil i Live Landmarks nyeste debattinnlegg på forskersonen.no. Hun påstår at bare 17 av hundrevis av personer med ME-diagnose endte opp med en reell ME-diagnose etter medisinsk undersøkelse. Dette er helt feil (se bilde). Det var bare 4 stk som endte opp med annen diagnose,
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Algebraic @algebraic-ug.bsky.social · 15/03/2026
Squishy Volumes: MPM Desert Space Ship Scene (6M+ Particles) A futuristic Sci-fi spaceship emerges from the desert sand. Made with Squishy Volumes, a free MPM Blender Add-on developed by Algebraic! Check out this blog post for a behind-the-scenes: algebraic.games/blog/desert_...
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Andreas Longva @andlon.bsky.social · 15/03/2026
Stumbled upon this very nice talk by @justinmsolomon.bsky.social on optimization in geometry processing. I really enjoy this "zoomed out" perspective. It's very useful for someone like me, who works in a field adjacent to geometry processing (physics sim) and can perhaps use some of the same ideas!
youtu.be
Distinguished Seminar in Computational Science and Engineering: Justin Solomon, 12/11/2025
YouTube video by MIT CCSE
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Maike Osborne @maosbot.bsky.social · 15/03/2025
When I got Long Covid, I was 38 and healthy. If you are anything like I was then, it is hard to understand how bad Long Covid is. I think that we all have an instinct to just… look away. But, please, it is important that you look. #LongCovidAwarenessDay
The image shows a person standing in what appears to be a modern convenience store or small market. They're wearing a light blue button-up shirt and yellow pants, with sunglasses tucked into their shirt collar.
They're positioned next to a candy display section clearly labeled "CANDY" with various confectionery items on shelves. The wall behind them has white subway tiles with orange text that reads something about "NO CHECKOUT" and "WALK OUT SHOPPING," suggesting this might be an automated store where customers can take items and leave without traditional checkout.
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