At
GDC 2026,
NVIDIA and
CD Projekt RED showed a demo of the Polish studio's
The Witcher 4 using NVIDIA's
RTX Mega Geometry to path trace forests for the first time.
Now, NVIDIA has
released the full video replay of the GDC 2026 session '
The Future of Path Tracing | Best Practices, Optimizations & Future Standards', which includes lots of interesting details on that The Witcher 4/RTX Mega Geometry demo.
Martin Stich, Senior Director of Engineering at NVIDIA, introduced the company's latest work based on Mega Geometry:
a level-of-detail system for foliage. He notes that no new APIs or hardware are required, since it is built on the existing Mega Geometry APIs.
The demo scene, which includes tree assets provided by CD Projekt RED (presumably used in the development of The Witcher 4), features
60 million plants of 200 different species and around
1 million trees. It takes place on a
5×5 km terrain, entirely held in memory with no streaming, as evidenced by the lack of any pop-in or other typical LOD issues.
Larger trees have up to and over
10 million polygons each, and everything in the demo is modeled as actual geometry, meaning no alpha maps or cards, down to individual pine needles. Martin's favorite stat from this demo, though, is that if you flattened the entire scene into a triangle list at full LOD, you would get
over 5 trillion triangles. Of course, The Witcher 4's RTX Mega Geometry foliage demo features fully dynamic path-traced lighting with
pixel-perfect shadows, and everything can be
uniquely animated.
NVIDIA has unveiled the performance breakdown for The Witcher 4's RTX Mega Geometry foliage demo: 4K@80FPS on a GeForce RTX 5090.
wccftech.com