Unleashing the Power of RTX Mega Geometry in Alan Wake 2

It has been more than six years since the initial consumer-level graphics cards were introduced that enabled hardware-accelerated ray tracing, and although technology has significantly advanced since the launch of Nvidia’s Turing architecture in 2018, these advancements have also been complemented by innovations in software development. RTX Mega Geometry was unveiled at CES 2025, showcasing a series of captivating demonstrations; however, we now have our first example of this technology in a commercial game: Alan Wake 2. There are enhancements in quality, efficiency, and performance, but perhaps the most surprising finding in our analysis is that the RTX 20-series and 30-series GPUs offer the greatest support.

Let’s start with the fundamentals – what exactly is RTX Mega Geometry? This requires a comprehension of the way ray tracing functions. As it currently stands, every game effectively generates two 3D worlds – the environment as you perceive it during gameplay and a secondary ‘BVH structure’ which is essentially a simplified version of the scene. BVH stands for bounding volume hierarchy. Rays are projected into the BVH structure, and their trajectories are subsequently calculated. As you can assume, ray tracing itself is compute-intensive, so building and querying the BVH structure adds to the computational load. Additionally, there are challenges – while the game world may be visually arresting, it doesn’t guarantee that the BVH will be, leading to potential discrepancies and a loss of visual fidelity.

Enter RTX Mega Geometry, which is essentially a new API that introduces an innovative design and hierarchy for the BVH structure, incorporating the game world’s geometry and assets. The primary focus is on detailed geometry, support for a greater number of level-of-detail transitions, and adaptive tessellation, where the amount of actual geometry per frame continuously varies. Mega Geometry adds a new element to the BVH structure: the CLAS or Cluster Acceleration Structure. While the increased complexity adds to the ray tracing time, there is a remarkable increase in detail and support for immersive environments.

RTX Mega Geometry is essentially Nvidia’s branded version of a widespread shift in RT APIs that could potentially be embraced by all manufacturers. In a landscape where mesh shading, Epic’s Nanite, and the essential need for immersive environments are taking the spotlight, the current DXR APIs are no longer truly suitable for their purpose – all of which brings us to the specific implementation found in Remedy’s Alan Wake 2.

This title represents an exceptional case for RTX Mega Geometry, as the game world is rich in detail through mesh shading and is visually stunning. In Alan Wake 2, geometry is physically engaging and dynamically altering, unlike merely ‘faking’ it with a vertex shader. Altogether, this complexity makes integration with an existing BVH structure challenging. Numerous optimizations are put in place to enhance performance, such as reducing animation rates for objects further away from the player. The first 10 meters utilize full frame rates, followed by half, third, and quarter rates as distance increases. On PS5, this rate is halved further. The nearest objects operate at half-speed, while significantly important characters move at full speed.

RTX Me