Ray tracing is a graphics rendering technology that simulates the physical behavior of light to produce more realistic images. Long reserved for animated films and special effects, it has recently made its appearance in real-time in video games, bringing a notably improved visuals to certain titles. This change is due to advances in hardware and software that now make this type of continuous, frame-by-frame calculation possible.
What is ray tracing used for?
Ray tracing is based on a principle that’s fairly simple to understand: it simulates rays of light that leave the camera, cross a 3D scene and interact with the objects present. Each time a ray encounters a surface, it may be reflected, refracted or absorbed, depending on the properties of the material. These interactions determine the final appearance of the pixels on screen. In practice, this results in precise reflections, soft, realistic shadows and more natural ambient light. Unlike traditional rendering methods, which use approximations to display a bright scene, ray tracing is based on the physical laws of light.
In practical terms, this changes a number of things in a game. For example, a mirror can faithfully reflect a dynamic scene with its characters, shadows will be more diffuse and natural depending on the angle and distance of the light source, and materials such as water, glass or metal will appear much more believable. This also allows for more subtle effects, such as indirect lighting: light can bounce off a colored wall and influence the hue of a nearby object, reproducing what we observe in real life. In a game like Cyberpunk 2077, switching ray tracing on and off often gives the impression of a change in graphics generation.
How does ray tracing work?
From a developer’s point of view, ray tracing transforms the way light is conceived in a scene. Historically, games have used rasterization, a method that projects 3D objects onto a 2D plane and applies visual effects using algorithms. This requires a great deal of trickery: fixed lights, textures simulating reflections, and pre-calculated shadows in some cases. Although highly optimized, these methods have always had their limits in terms of realism. With ray tracing, developers can do away with many of these complex steps. They can focus more on the physics of the materials and the overall lighting of the scene, rather than on manually reproducing effects.
That said, video game ray tracing is not yet used in its entirety. For performance reasons, studios often use it in fragments. A graphics engine may activate ray tracing only for reflections or shadows, while retaining more conventional rendering for the rest. This compromise enables visual benefits to be achieved without severely compromising fluidity. At the same time, tools such as DirectX Raytracing (DXR), OptiX or Vulkan RT facilitate the implementation of these techniques in modern engines. Unreal Engine, for example, offers hybrid solutions combining rasterization and ray tracing, enabling priorities to be adjusted according to the visual needs of the game.
Performance with ray tracing
One of the major challenges of ray tracing is its resource-hungry nature. Each ray launched must interact with the environment in a coherent way, which generates a considerable volume of calculations, especially when aiming for a smooth display at 60 frames per second or more. In general, the higher the number of rays per pixel, the cleaner the result, but this significantly slows down rendering. This is why only recent graphics cards, such as GeForce RTX or high-end Radeon RX, are capable of handling this load in real time.
To get around this problem, GPU manufacturers have developed upscaling technologies. Nvidia offers DLSS (Deep Learning Super Sampling), while AMD offers FSR (FidelityFX Super Resolution). The principle is similar: the game is rendered at a lower definition, then the image is enlarged to the screen’s native definition using algorithms. In the case of DLSS, this relies on a neural network trained to reconstruct details with good fidelity. FSR, which is more universal, is based on a simpler method that is less costly to implement. These techniques make it possible to maintain a high framerate while preserving a good level of image quality, and they have become almost indispensable as soon as a game activates ray tracing on an extensive scale.
Path tracing: taking it a step further
Path tracing is an advanced rendering method that takes the principles of ray tracing a step further by simulating the path of thousands of light rays per pixel with a probability-based approach. Unlike conventional ray tracing, which follows a few well-defined rays to calculate reflections and shadows, path tracing lets rays bounce randomly off scene surfaces until they reach a light source or are absorbed. This approach enables a highly accurate reproduction of overall lighting, including complex effects such as indirect illumination, subsurface diffusion and caustics.
On the other hand, path tracing requires an enormous amount of computing power, making it difficult to exploit in real time in video games. It is mostly found in rendering engines used for computer graphics, animation or architectural previews. However, some recent game engines are beginning to offer experimental real-time path tracing modes, in Cyberpunk 2077 and Portal RTX for example, by combining this technique with optimizations such as DLSS. The final rendering is often more realistic, but requires high-performance hardware to maintain fluidity.
How to get the most out of ray tracing
To take full advantage of ray tracing, it’s not enough to have a compatible graphics card. The screen on which the game is displayed plays a fundamental role. A monitor or TV capable of reproducing a high dynamic range (HDR) allows you to better perceive the luminous nuances produced by ray tracing. This is even more true if the device is Dolby Vision or HDR10+ compatible, formats that optimize scene-by-scene or frame-by-frame display.
Image resolution is also important. Ray tracing can provide real benefits at 1080p, but it’s at 1440p or 4K that details become more visible. Reflections, shiny textures and shadow effects are better expressed at high definition. That said, the higher the definition, the greater the load on the GPU. Here again, technologies such as DLSS and FSR make it possible to aim for 4K without sacrificing fluidity. On consoles, the PlayStation 5 and Xbox Series X offer ray tracing in certain games, but often only partially and at variable definitions, sometimes with a significant drop in frames per second.
- Read the guide: How can I benefit from Ray Tracing?
The best video games with ray tracing
Many recent games incorporate ray tracing to enhance visual rendering, providing more realistic light, shadows and reflections. This technology is used in a wide range of titles, from narrative games like Alan Wake 2 or Control to open worlds such as Cyberpunk 2077, The Witcher 3 and Dying Light 2. It can also be found in stylized productions like Minecraft RTX or Lego Builder’s Journey, as well as in recent blockbusters such as Indiana Jones and the Great Circle, Spider-Man 2, Star Wars: Outlaws and Avatar: Frontiers of Pandora. Ray tracing has gradually established itself as an advanced graphics option in a wide range of games for PC and modern consoles.
| Cyberpunk 2077 | Indiana Jones and the Great Circle |
| Metro Exodus | Control |
| Lego Builder’s Journey | Minecraft |
| Alan Wake 2 | Dying Light 2 |
| Portal RTX | Spider-Man Remastered |
| Spider-Man: Miles Morales | Spider-Man 2 |
| GTA V | Ghostwire: Tokyo |
| The Witcher 3: Next Gen | Teardown |
| Hitman | Wuthering Waves |
| Quake II RTX | Dragon’s Dogma 2 |
| Avowed | Kingdom Come: Deliverance 2 |
| Star Wars: Outlaws | Avatar: Frontiers of Pandora |
| Lego Fortnite | Zombieville USA 3D |
| Doom Eternal | Doom: The Dark Ages |
Ray tracing marks a milestone in the quest for realism in video games. It’s not just a graphics enhancement, but a paradigm shift in the way light, reflections and shadows are simulated. While its adoption is still partial, it is gradually spreading as hardware becomes more powerful and development tools become richer. Compromises are still necessary, both technically and in terms of gameplay, but the results achieved already show clear progress. For gamers, this represents a visible qualitative leap in compatible games, provided they have the right equipment. In the years to come, as GPU performance increases and technologies such as DLSS continue to advance, ray tracing could well become a de facto standard in AAA games.
Frequently asked questions about ray tracing
Ray tracing enhances visual realism by adding precise reflections, soft shadows and improved light management. This contributes to greater immersion, especially in complex environments.
Rasterization rapidly projects 3D shapes in 2D onto the screen, without simulating light realistically. Ray tracing, on the other hand, follows light rays for a more accurate rendering, but requires more computing power.
Yes, especially for reflections, global lighting and shadows, which become much more realistic. But the difference depends on the game, the environment and the level of implementation.
Yes, consoles such as the PS5, Xbox Series X|S and Switch 2 support certain ray tracing functions. Effects are often limited compared to PC, to preserve fluidity.
Some older cards can technically do this, but performance will be insufficient for comfortable use. Rendering may be slow, or even unplayable.
It can drastically reduce the number of frames per second, especially without upscaling technologies. The trade-off between visual quality and smoothness is therefore important to consider.
Path tracing is a more complete and realistic version of ray tracing, simulating hundreds of light bounces per pixel. It is even more demanding and rarely used in real time.
