Xiangshun Bei

Tech Lead/Senior Graphics Engineer @NVIDIA. Ex-Graphics Engineer @EA and @Qualcomm. USC Trojan. Amateur cyclist. Opinions are my own.

[Xiangshun Bei @bxs3514]

Excited to release our Character Rendering SDK with real-time path-traced hair & SSS! Dive into the details of our innovative RT Hair BCSDF & RTSSS technology: https://t.co/6bAo7GBPM9
Huge thanks to @PawPawDH for his groundbreaking LSS work! Learn more in the tech blog:

[NVIDIA Game Dev @NVIDIAGameDev]

Render path-traced hair in real time.⚡

Available today, developers can use linear swept sphere (LSS) to ray trace hair and fur through the NVIDIA RTX Kit on GeForce RTX 50 Series GPUs.

https://t.co/LpMP3IGlCz

[Kostas Anagnostou @KostasAAA]

Understanding The Math Behind ReSTIR GI https://t.co/8W5v4yq7yI

[Jacob Freeman @GeForce_JacobF]

RTX Hair coming in a future update to Indiana Jones and the Great Circle. It uses Linear-Swept Spheres for improved performance, better image quality and lower VRAM usage. 👍

[Daqi Lin @DaqiLin]

Excited to share our new ReSTIR work! Our Area ReSTIR fixes regions where reuse breaks. It's simple to be implemented on ReSTIR DI/GI/PT. Check the paper and @SongZhang__ 's code for details.

[Xiangshun Bei @bxs3514]

A must-read course if you want a deep understanding of ReSTIR algorithm(s)

[Chris Wyman @_cwyman_]

The video for our SIGGRAPH 2023 course "A Gentle Introduction to ReSTIR" is now available on the ACM Digital Library. It's freely available, without subscribing to the DL, by navigating through this specific link (our course is first): https://t.co/ybeYsuuHuW

[Xiangshun Bei @bxs3514]

@Jiayin_Cao Yes I think you are correct. My first comment was actually not a good example. This is more like integral(f(x)dx)+integral(g(y)dy), no issues if just unify the notation but keep the actual functions separated.

[Xiangshun Bei @bxs3514]

@Jiayin_Cao No. This is properly not the problem, just noticed x's are i.d.d then the jacobian can be cancelled out.

[Xiangshun Bei @bxs3514]

@Jiayin_Cao Is this missing the changing of variable? E.g. <I> = integral f(x0)dx0 +integral f(x1) dx1, you basically need to change the integral f(x1) dx1 to integral f(x0) |J(∂x1/∂x0)|dx0, then <I> = integral (1+Jacobian)f(x0)dx0

[Markus Kettunen @nmkettunen]

Thrilled to announce our work "Conditional Resampled Importance Sampling and ReSTIR" (SIGGRAPH Asia 2023). We extend RIS and ReSTIR into conditional probability spaces, enabling novel forms of sample reuse. 1/7

[Adam Marrs @acmarrs]

Essential: https://t.co/wcYHbRgX2o

[AJ @AurelioReis]

Nsight Graphics 2023.3 is out with a brand new feature that is going to change the way you profile and optimize shaders: the Realtime Shader Profiler in GPU Trace. Download & more info here: https://t.co/ArRL09Fbvh

#NVIDIA #NsightGraphics #Nsight #Shaders #Profiling #Raytracing

[Xiangshun Bei @bxs3514]

@yongyuanxi おめでとう🎉　Siggraph Asiaで？

[NVIDIA GeForce @NVIDIAGeForce]

RTX IO introduces ground-breaking GPU decompression for:

🟩 Faster texture load times
🟩 Lower CPU utilization
🟩 More efficient disk space usage

RTX IO is here today in Portal: Prelude RTX, and July 26th in Ratchet & Clank: Rift Apart.

Read 👉 https://t.co/GQvU16cXNh

[Xiangshun Bei @bxs3514]

@AllaSheffer Feels like it’s irresponsible and not professional on the review work, afaik it’s rare cases that the entire idea goes wrong unless it’s a super new area, while the paper has shown decent coverage. Hope this kind of things happen less in our graphics community.

[Adam Marrs @acmarrs]

Heads up: the NVIDIA RTX branch of UE *5.1* just got updated with RTXDI functionality in Lumen.

Both branches received bug fixes and other improvements too.

[Yining Karl Li @yiningkarlli]

Johannes Hanika has posted the notes for this year's SIGGRAPH Path Tracing in Production course. This year's course consists entirely of Avatar stuff, which as you'd expect from Weta, means the fanciest advanced light transport devised by mankind to date:

https://t.co/cVgQ5xmLFz

[Jiayin Cao @Jiayin_Cao]

When I first read ReStir DI, it took me quite a while to understand how it works.

So I put down some notes during my learning process in a new blog post. I hope this could be helpful.
https://t.co/FQM4HoLzV6

[Xiangshun Bei @bxs3514]

@AmazingThew Fine fact, it can be caused by the float precision curve I think. Could be hard to conquer, the only strategy is using as much as unnormalized screen space coordinate imo

[Xiangshun Bei @bxs3514]

@m_ninepoints It’s called framebuffer fetch if I didn’t remember it wrong

[Xiangshun Bei @bxs3514]

@m_ninepoints It’s possible to do so in the some mobile GPUs with ext, because there’re some tricks on its cache-like GMEM. But it’s still be very challenging for the synchronization and memory management; and need special hw to accelerate it.