SIGGRAPH Advances in Real-Time Rendering
7 HN recommenders · recommended in 11 months, 2021–2026
1:10:00 · 279K views · Oct 30, 2021
Brian Karis's SIGGRAPH 2021 talk explains how Unreal Engine 5's Nanite virtualized geometry works. It covers mesh import, the data structures, streaming, decompression, culling, software and hardware rasterization, and shading.
HN treats it as the definitive deep dive on Nanite, admired for the engineering ambition behind pixel-sized triangles and compute-driven rendering.
20 comments from Hacker News
It attracts truly extraordinary talent. One of many examples: this video . There is more technical ambition in a single slide of that project than an entire department at places I've worked. However, it also tends to demand more and pay less, so there is churn and burnout and when it comes time to triage, the triage can cut very deep. If I were to dive into the JIRA for any one of these "missing compression" incidents, I wouldn't expect to find an easy win, I would expect to find "missing compression" beneath a pile of much worse bugs like "level 2 crashes on AMD cards." So it goes.
For real. The talent in the game industry is insane. Recently, I got my mind blown by the Unreal Nanite team: this video The core of it is a respectably sophisticated LOD building algorithm, as you might expect, but the sheer amount of engineering horsepower they put into driving it into production just boggles the mind.
If this UE5 demo is using Nanite, then it really may well just be modeled geometry. Nanite really blurs the line between geometry and texture - in a sense it’s a shader that uses triangle mesh data as if it were a texture source. This siggraph session will expand your mind: this video
Nanite has a large pre-render step, but it also changes the rendering quite significantly. (Which in some cases includes a software rasterizer running on the GPU) This is a really good deep dive if you’re interested: this video
Their YouTube channel has the excellent deep dive on the unreal engine's nanite virtual geometry system: this video The one on idTech8 global illumination from last year is pretty interesting too.