"Witcher 4 will get this path-traced foliage system for dense forests
NVIDIA RTX Mega Geometry is adding a dedicated foliage system, previewed at GDC 2026.
Dense natural environments remain a hard problem for path-traced real-time rendering. Foliage scenes combine high geometric complexity with per-frame animation, which means the GPU has to rebuild bottom-level acceleration structures constantly – at a scale that's historically made full path tracing impractical for forests and large outdoor environments.
The new system uses partitioned top-level acceleration structures to instance and update large portions of the scene every frame, decoupling the update cost from raw triangle count. The result is a path-traced rendering of millions of individually animated foliage elements without the per-frame BLAS rebuild overhead that makes this prohibitive with standard BVH approaches.
RTX Mega Geometry compresses geometry into reusable clusters and builds ray-tracing acceleration structures 100x faster than previous methods, with support for real-time tessellation. Remedy's implementation in Alan Wake 2 demonstrated baseline gains: 5-20% FPS improvement and 300 MB VRAM reduction on existing assets, without changes to the content. The foliage system extends the same architecture into scene types where the geometry-to-animation ratio makes standard approaches break down.
CD PROJEKT RED has been announced as the partner for the foliage tech, targeting The Witcher 4."
https://developer.nvidia.com/blog/nvidia-rtx-innovations-are-powering-the-next-era-of-game-development/
