Raytracing Director at Nvidia. Previously: Tech Lead for RenderMan at Pixar, Architect of Glimpse Renderer at Animal Logic 🇮🇹🇦🇺🇺🇸🇨🇦 Views are my own.

The pale blue dot
Joined July 2013
Weekend project: now I can enjoy a good tv show while working out.
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It's a rainy day, and I haven't done anything in a while. So, I coded some tiny transition animations on the Workbench manipulators. Lowe effort, kind of fun.
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Max Liani retweeted
Can't believe Serj and Corey would make a song with that one guy after all his awful crimes (his music).
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So apparently ChatGPT invites people to generate 80s pictures. I wasn’t one of the cool kids, so I thought this generated alternate take was fun enough to post.
🤖 Made with AI
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We're doing a livestream on Warp tomorrow, come talk simulation with me!
How is NVIDIA Warp accelerating computational engineering and robotics applications? Join tomorrow’s livestream to see how this open-source CUDA-X library helps developers accelerate GPU-accelerated Python workflows for simulation, computational engineering, and robotics. We’ll walk through a practical computational engineering and robotics workflow and use cases, and show how NVIDIA Warp is used that reached 10 million downloads. You’ll learn how to: ✅ Apply Warp to computational engineering and robotics workflows ✅ Build high-performance simulation code in Python ✅ Get started with NVIDIA Warp 📅 September 2, 2026 @ 11 AM PT 👉 Register: nvda.ws/4zPqFEV
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I haven’t developer much lately, too busy at work. But perhaps I could post some light reading about some of the stuff I have done in the previous year… Anyone interested in how to design a good unit testing framework? One for lightweight white-box testing (my favorite style).
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Max Liani retweeted
when you say "life is a stochastic path integral" instead of "shit happens"
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Also, remember that each subexpression is a separate conditional jump. So, if you are working on some high performance portion of you program, consider using long-circuit logic operators when each subexpression is trivial: if(bool(trivial_test1) & bool(trivial_test2))…
Every sub-expressions in my if() statements are ordered based on expected cost + expected likelihood of failing. if (cheap_test && costly_test) if (likely_to_fail && unlikely_to_fail) Even with imperfect heuristics it still feels like common sense to pay attention to that.
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That’s particularly valuable on certain compilers that don’t seem to optimized subexpressions, like MSVC. But you also have to pay attention to branch prediction, sometimes a combined test is less predictable than two separate tests.
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For these things I tend to write my perf guess from intuition (it doesn’t add complexity). Then when I come to it, I profile with VTune and check branch prediction and pipeline stalls counters. At first one may not have the intuition, so you rely more frequently on the profiler.
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So, the agent “accidentally applied” auto formatting, introducing hundreds of changes, it then realized what it did and it’s going through them one by one to restore the original code… way to burn down tokens!!
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Today is a good day.
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The Food and Drugs Administration initiated a review to request adoption of nutrition facts labeling for any catalogued celestial body.
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Coming back from Japan, I got in the habit of cooking onigiri.
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Hollywood has spent nearly $600 million trying to bring Matt Damon home. Have they considered maybe he just doesn’t want to come back?
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Maybe I see this in rosy retrospection, but I feel that the work I did many years ago to create the Glimpse production renderer still feels to me the most insane project I ever started.
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About 3.5 years ago I did some experiment to improve the behavior of microfacet normals at glancing angles. Many surfaces become highly reflective even though having high roughness. Check the discussion in the thread. Here is my implementation reusing equations you already have:
There's a neat short paper from Eurographics this year that evaluates how well microfacet shading models actually predict measured reflectance. The answer is: not nearly as well as one would hope! (1/3) ssteinberg.xyz/2026_surface_…
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A sketch from my notes for intuition:
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Cut tool. It does more or less what you'd expect from a cut tool. Snap to points and edges, fractional placement, cut across faces, slice. No support for edge loops yet.
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