Here’s Why Ray Tracing and Path Tracing are still not the default render mode for games

It’s been half-a-decade since NVIDIA released the GeForce RTX 20-series cards. the first ever consumer graphics cards that can do real-time ray tracing*. While NVIDIA danced around the technicality of ray tracing, they succeeded in conveying the difference between traditional raster and a ray-traced scene is. While video games have only had a taste of ray tracing in the last couple of years, the movie industry and its ever-growing reliance on computer generation imagery (CGI) especially with even simple productions now running a gamut of CG scenes, ray tracing or its much more complex counterpart, path tracing, has helped entertainment media flourish.

Movie CGI is a large culmination of different things from how the shots are filmed, how acting performance is captured, prepped for compositing all the way to the components of making the CG scene, from modelling, lighting, to working with tools that allow highly dynamic and more importantly, realistic effects to make a scene. The final image sequence all forming a motion picture featuring anything from highly cartooney to very realistic.

And to achieve this realism, both games and CG rely on ray tracing and/or path tracing. Today we enjoy (somewhat) ray tracing on games as a real-time feature but this there workarounds to achieve this faster render time because ray tracing and path tracing are highly complex and very computationally demanding.

I’ve always admired the academic explanation of path tracing and ray tracing. But the mathematic, geometric and physics concepts of it best describe the actual process. This does go over the head of many people so a visual explanation is best.

In the video above by Branch Education, we see an in-depth look at how ray tracing and path tracing are done to give us the most realistic images in the 3D world. It shows the simple concept behind path tracing and ray tracing and explains the current steps we take in terms of both CG for movies and games and how this is currently being achieved.

Easily the best explanation for the layperson done on the subject.