The Witcher 4 is intended to add RTX Mega Geometry technology. Recently, NVIDIA showed it in action using a forest as an example:
Realistic, large-scale natural environments, such as forests, remain a serious challenge for real-time ray tracing rendering. Such scenes require a huge number of objects with complex geometry and continuous animation. This significantly increases the load on ray tracing, the performance of acceleration structures, and video memory requirements. We are developing a new level of detail system for vegetation to cope with all these problems. This technology selectively updates the scene and presents levels of detail in a way that is compact in memory, visually seamless, and efficient for ray tracing.
RTX Mega Geometry technology allowed "for the first time to perform full path tracing" in dense environments with millions of detailed plants, unique animation, and accurate real-time lighting.
CDPR specialists are working together with Epic Games and NVIDIA to implement RTX Mega Geometry:
Our vegetation system is based on existing mega geometry APIs, and later this year we will present open source code. We are pleased to cooperate with developers such as CD Projekt Red to implement this technology in future projects.