Ray tracing and path tracing are advanced lighting techniques used in games that have caused controversy between gamers and GPU manufacturers. Ray tracing, a technique for modeling lighting in a scene, has been used in film CGI for many years, but is difficult to calculate in real time in games. It works by pointing a beam at a scene and calculating its interaction with objects and light sources, resulting in very realistic lighting effects. Nvidia RTX graphics cards have made real-time ray tracing possible in games, from shadows and reflections to global illumination.
On the other hand, path tracing is a more modern method that handles dynamic lighting in real time. Send multiple rays from a light source and track their random reflections in the scene. While more complex on the surface, path tracing is easier to render than ray tracing because it traces a sample of rays rather than every single ray from pixel to source. Combine ray tracing with Monte Carlo simulation to achieve ray tracing like lighting effects at a lower cost and with greater detail depending on system capabilities and configurations.
Path tracing can produce images as impressive as ray tracing, while requiring less rendering resources. It has been used in impressive ray tracing games such as Quake II RTX and Portal RTX, as well as older games such as Half-Life 2. However, there are certain scenes, such as those with reflective and refractive objects, where path tracing may be needed. . be tweaked or replaced with coarse ray tracing to achieve higher fidelity.
In terms of performance, ray tracing is computationally intensive and can overwhelm even modern hardware. Therefore, games that claim to support ray tracing often use it selectively for shadows or reflections. Path tracing offers a higher quality, less intense form of dynamic lighting, making it an attractive alternative. However, both methods have their place in game development. Until the hardware gets to the point where it can easily display either ray tracing or path tracing, it’s likely that future games will use a combination of lighting effects to take advantage of each technique.