The problem is that although it scales better than rasterization, the computations involved in tracing are much more expensive (on current hardware at least).

The problem is that although it scales better than rasterization, the computations involved in tracing are much more expensive (on current hardware at least). Another big drawback of ray tracing is that you can't use conventional occlusion and view frustum culling [1] with it. So significantly reducing the scene size, as you do in a rasterization renderer, is just not possible. If you have access to the GDC Vault I can recommend DICE's 2019 talk about reflections in Battlefield V. The slides are available for free [2]. [1] https://media.giphy.com/media/xUPGcgiYkD2EQ8jc5O/source.gif https://media.giphy.com/media/xUPGcgiYkD2EQ8jc5O/source.gif From the game Horizon Zero Dawn. Only geometry that might end up on the screen is actually sent through the rasterization pipeline. [2] https://gdcvault.com/play/1026282/It-Just-Works-Ray-Traced https://gdcvault.com/play/1026282/It-Just-Works-Ray-Traced Talk about culling starts on slide 56. Occlusion and Frustum culling aren't an option, so new techniques had to be developed.