Christopher Batty
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topher-batty.mastodon.acm.org.ap.brid.gy
Christopher Batty
@topher-batty.mastodon.acm.org.ap.brid.gy
68 followers 16 following 56 posts
Associate Professor in CS at University of Waterloo doing computer graphics and computational physics. I also manage https://physicsbasedanimation.com […]

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topher-batty.mastodon.acm.org.ap.brid.gy
There's a new and very neat-looking SIGGRAPH Asia paper on constructing the swept volume based on the path of a moving (possibly deforming) object. Check it out!

https://jurwen.github.io/Swept-Volume-Page/
A rather strange twisted-looking smooth shape generated as the volume of space swept out by a rotating and translating sculpture. The left shows an opaque rendering, the middle shows the same shape with surface points colored to indicate the time, and the right shows a semi-transparent view.
November 20, 2025 at 1:07 AM
topher-batty.mastodon.acm.org.ap.brid.gy
Not a new phenomenon, but the contortions that newspapers go through to avoid saying "Trump is lying" continue to amaze.
A Washington Post headline saying "Trump's Venezuelan boat claims obscure reality, officials and locals say".
October 20, 2025 at 4:06 PM
topher-batty.mastodon.acm.org.ap.brid.gy
If you haven't heard of it, "Curl Noise" is a neat procedural trick to produce incompressible fluid-like flows by pushing a noise field through the vector calculus curl operator.
See: https://www.cs.ubc.ca/~rbridson/docs/bridson-siggraph2007-curlnoise.pdf
A static two-dimensional fluid flow visualized by small particles with trails, and there is a solid disk blocking part of the flow. The flow is mostly smooth, but downwind of the circle the flow becomes noisy and turbulent.
October 10, 2025 at 2:34 PM
topher-batty.mastodon.acm.org.ap.brid.gy
I just learned about the Blaschka glass flowers and sea creatures, produced in the late 1800s. Amazing!
https://en.m.wikipedia.org/wiki/Glass_Flowers
https://en.m.wikipedia.org/wiki/Glass_sea_creatures
An impressive glass recreation of what looks like a kind of sea anemone with delicate tendrils branching off from a central stem, apparently called a Devonshire cup coral.
September 8, 2025 at 3:53 PM
topher-batty.mastodon.acm.org.ap.brid.gy
On a work-related note: for those attending SIGGRAPH North America 2025 in Vancouver, I'll be chairing the intriguingly named session "This is Fluid Simulation", bright and early on Monday morning at 9am. Mark your calendar!
https://s2025.conference-schedule.org/session/?sess=sess138
An image from the movie "300" overlaid on a black background, with Gerard Butler as Spartan King Leonidas holding a sword in menacing fashion in front of a battlefield of defeated warriors, mostly with arrows sticking out of them. Christopher Batty's smiling face is pasted over top of Butler's. The image is sometimes associated with Butler's quote in the movie hollering "THIS IS SPARTA!!", but in this case the words "THIS IS FLUID SIMULATION" appear at the bottom of the image.
July 26, 2025 at 4:57 PM
topher-batty.mastodon.acm.org.ap.brid.gy
My TV is now kindly offering to "Surprise Me With AI Art". Look, there are some plausible use cases for some kinds of "AI", but paying my TV to spring random AI slop images on me whenever I pause Netflix to get a snack from the kitchen is not and will not ever be one...
A TV screen showing a scenic blue ocean view from above with three rocky outcroppings or islands, overlaid with a small highlighted purple button labeled "Surprise Me With AI Art -- Try AI Art". A second button shows the date.
June 18, 2025 at 2:01 AM
topher-batty.mastodon.acm.org.ap.brid.gy
Here's an image showing some of the applications of CPM to surface PDEs from the thesis (diffusion curves, vector field design, geodesic distances, reaction-diffusion patterns, harmonic mapping).
6 shapes on a white background illustrating different applications of the closest point method. Top-left: a Nefertiti bust with various colors applied to its surface, illustrating diffusion curves. Top-middle: a Mobius strip decorated with arrows illustrating vector field design. Top-right: a torus with a black curve, and colored isocontours illustrating geodesic distance computation. Bottom-left: a fish-shape with reaction-diffusion patterns on its surface. Bottom-rigth: two deformed torus-shaped rubber duck objects with a texture, demonstrating harmonic mapping between the two.
May 20, 2025 at 2:07 PM
topher-batty.mastodon.acm.org.ap.brid.gy
It's reference letter writing time again! I always enjoy the grammatical/typographical errors that appear in the forms themselves.

This one raises the important question: is the student an applican, or an applican't?
A review form for a grad school reference letter, where the question is "Rate the applican'ts academic and intellectual ability" with various percentile options shown. There is an erroneous apostrophe appearing in the word applicants, like in the word "can't".
December 9, 2024 at 8:43 PM