What is Ray Tracing in Games?

Ray tracing is a feature you’ll see mentioned with the latest Nvidia RTX 50 Series graphics cards as well as AMD’s new Radeon RX 9070 XT and RX 9070. It’s used in modern games to produce incredible visuals and relies on specialized hardware in today’s GPUs, which is why Nvidia, AMD, and even Intel highlight the technology with every new hardware release.

Ray tracing is also used to give some classic games a new lease of life, as aptly demonstrated by the recent release of the Half-Life 2 RTX.

Let’s dive into what ray tracing is, where it’s used, the various effects it supports, the challenges it faces, and which games take advantage of it. So, without further ado, let’s get on it.

In gaming, ray tracing simulates realistic lighting. That’s it. Some of the effects it creates can be incredibly impressive, producing far more believable worlds than traditional rasterization can, but that’s essentially all it does. Lighting effects such as realistic shadows, reflections, translucency, and global illumination are all significantly improved with ray tracing over previous methods.

If you want to render a rain-soaked street with puddles reflecting neon signs and shop windows refracting light properly to build a convincing world, ray tracing is the way to go. This is why the technology is used so effectively in games like Cyberpunk 2077 and, more recently, the GTA V Enhanced update, to name just two from a growing list of ray-traced titles.

Because ray tracing accurately simulates how light interacts with objects in a scene, it can free up game artists to focus on creating the environments they envision rather than working around rasterization limitations. For this reason, ray tracing is often referred to as the future of game rendering, and there are plenty of examples to suggest that might be true.

When a developer implements ray tracing, they target specific effects and visual concepts. It isn’t just something they turn on – it’s a toolkit of effects, from the relatively simple, like shadows, to more complex techniques such as global illumination. Here’s a quick rundown of the main ray tracing effects:

Creating reflections with traditional rasterization is extremely challenging, if not impossible, without workarounds. Over the years, developers have used techniques like Screen Space Reflection (SSR), which can efficiently handle water reflections or duplicate a scene to create the illusion of a reflection. However, these methods have clear limitations—SSR, for example, only reflects what’s currently on screen, meaning objects outside the camera’s view won’t appear in reflections.

Ray-traced reflections, by contrast, accurately depict the game environment, significantly improving immersion. Mirrors, glass, puddles, and even subtle reflections on polished surfaces all benefit from true ray tracing. However, reflections can be computationally demanding, which is where AI-powered solutions like Nvidia’s DLSS 3.5 Ray Reconstruction come into play.

Game developers have been using shadow maps for years, but these have limitations—shadows can look artificial, suffer from resolution constraints, and struggle with dynamic lighting. Ray-traced shadows are far more realistic, especially when combined with other ray tracing techniques like global illumination.

Games traditionally handled lighting in very basic ways. Direct lighting added a touch of believability, but the result could still look cartoonish. As games have become more detailed and richer, the demand for realistic lighting has increased to the point where the subtle interplay between materials, surfaces, and secondary lighting is essential. Traditional rasterization pre-baked lighting to create a more believable, solid world, but this came at the cost of dynamism. When something moved, the lighting could feel off because it lacked the ability to react realistically.

Ray tracing once again leaps to the rescue by handling lighting with a greater degree of accuracy, making for a more immersive environment. It simulates both direct and indirect light to produce a more believable scene. One that is dynamic and tonally much closer to what you see in the real world. The effects of ray-traced global illumination can be subtle, especially in natural settings like a dense jungle, but your brain picks up on the right cues and it just makes more sense than pre-baked lighting ever could.

Ray tracing has faced significant challenges. For starters, it’s incredibly computationally expensive and requires dedicated hardware. A modern, powerful graphics card is essential to fully experience the technology.

Even with the latest GPUs, it’s not feasible to trace every single light ray in a scene at smooth frame rates. This results in noisy images that require post-processing to clean up. Because of these limitations, most games render ray-traced scenes at a lower resolution and use upscaling techniques like DLSS or FSR to maintain image quality.

Another hurdle is that not all games support ray tracing. It’s not as simple as buying an RTX 50 Series card and suddenly seeing every game transformed. The good news is that Microsoft’s DirectX 12 includes built-in ray tracing support, making it easier for developers to implement.

One final challenge is that traditional rasterization has become extremely good at simulating realistic lighting. It still relies on approximations and clever tricks, and some effects are impossible without ray tracing, but developers have refined rasterization techniques to the point where the visual difference may not always justify the computational cost of ray tracing.

Real-time ray tracing has been around for a few years now, and plenty of games showcase what it can do. Here are some standout titles that highlight the technology:

• Alan Wake 2
• Black Myth: Wukong
• Control
• Cyberpunk 2077
• Ghostwire: Tokyo
• Indiana Jones and the Great Circle
• Marvel’s Spider-Man
• Metro Exodus
• Minecraft RTX
• Ratchet & Clank: Rift Apart
• Resident Evil Village
• Shadow of the Tomb Raider
• Watch Dogs: Legion

You can find a sortable list of ray-traced games on Nvidia’s website. While it focuses on Nvidia’s technologies, it’s still a useful resource for finding games that showcase ray tracing’s capabilities.