Cryengine vs Unreal Engine 5: two paths to real-time lighting
In the realm of game engines, achieving dynamic and believable global illumination is a key technical challenge. Two giants, Cryengine and Unreal Engine 5, propose radically different solutions to eliminate the need for static light preparation, each with its own philosophy and set of advantages. 🎮
Cryengine's approach: SVOGI and voxel rasterization
Cryengine bets on its SVOGI (Sparse Voxel Octree Global Illumination) system. This method does not use traditional ray tracing, but rather rasterizes the entire scene into a three-dimensional structure of voxels (volumetric pixels). This approach allows calculating how light scatters and bounces between surfaces in a completely dynamic way.
Main features of SVOGI:- Processes global illumination by converting geometry into a voxel mesh, which the engine updates in real time.
- Handles complex scenes with cohesive lighting, ideal for changing interiors and exteriors.
- Visual fidelity and detail depend directly on the voxel mesh resolution, which can affect performance.
SVOGI represents an alternative path to ray tracing, prioritizing a unified global illumination solution that updates every frame.
Unreal Engine 5's response: Lumen and hybrid ray tracing
Unreal Engine 5 introduces Lumen, a dynamic global illumination system that does employ ray tracing techniques. However, its power lies in being a hybrid and intelligent solution that adapts to available hardware.
Main features of Lumen:- Uses software ray tracing to calculate global illumination and reflections in most situations.
- Takes advantage of modern GPUs' hardware ray tracing when available, for greater fidelity and performance.
- Works directly with the scene's surface meshes, allowing it to capture fine and complex details that voxels might miss.
Final comparison: contrasting philosophies
The choice between these systems often goes beyond the purely technical. While SVOGI in Cryengine offers a unified voxel-based solution, Lumen in Unreal Engine 5 opts for the flexibility of ray tracing over real geometry. Both pursue the same goal: lights and shadows that react instantly without manual work, but their algorithmic paths and the visual results they produce mark a fundamental difference for developers. The decision may come down to trusting the efficiency of voxels or the precision of rays. ⚖️