What Is Ray Tracing?
Ray tracing is a rendering technique that simulates the physical behavior of light. Instead of relying on shortcuts and approximations to draw shadows, reflections, and lighting – which is how games have worked for decades – ray tracing traces the path of individual rays of light as they bounce off surfaces, pass through transparent materials, and cast shadows. The result is lighting that looks strikingly realistic, closer to what you see in a movie’s visual effects than what you would expect from a video game.
Think of it this way: traditional rendering fakes how light works. Ray tracing actually calculates it. That difference is what gives ray-traced games their unmistakable visual quality – reflections in puddles that actually show the world around them, shadows that soften naturally with distance, and ambient lighting that fills a room the way real light does.
In-Depth
How Traditional Rendering Works (Rasterization)
To understand why ray tracing matters, it helps to know what it replaces. Traditional 3D rendering uses a process called rasterization. The GPU takes the 3D geometry of a scene, projects it onto a 2D screen, and applies textures, pre-baked lighting maps, and various visual tricks (shadow maps, screen-space reflections, ambient occlusion) to approximate how the scene should look.
Rasterization is extremely fast. Modern GPUs can rasterize billions of triangles per second. But because it relies on approximations, it has obvious limits: reflections only show what’s already visible on screen, shadows are sometimes blocky or inaccurate, and global illumination (light bouncing between surfaces) requires heavy workarounds.
How Ray Tracing Works
Ray tracing flips the approach. Instead of projecting geometry onto a flat screen, the GPU fires rays from the camera (your viewpoint) into the scene. Each ray travels until it hits a surface, then the GPU calculates what happens:
- Does the surface reflect? If so, a new ray bounces off in the reflected direction, picking up the color and light of whatever it hits next.
- Does the surface transmit light? For glass, water, or translucent materials, the ray bends (refracts) and continues through.
- Is the surface in shadow? A ray is cast toward each light source. If something blocks the path, the point is in shadow.
- Does light bounce indirectly? Rays can simulate light bouncing off one surface and illuminating another – this is global illumination, and it makes indoor scenes look dramatically more natural.
This process is computed for millions of pixels simultaneously, potentially tracing billions of rays per frame. It is extremely demanding on hardware, which is why real-time ray tracing only became practical in gaming with the introduction of dedicated ray tracing acceleration cores in GPUs.
Types of Ray Tracing Effects in Games
Not all ray tracing is equal. Games can apply ray tracing selectively to different visual elements, each with its own performance cost:
| Effect | What It Does | Visual Impact | Performance Cost |
|---|---|---|---|
| RT Reflections | Accurate reflections on shiny and wet surfaces | High – reflections show the full scene, not just what’s on screen | Moderate to heavy |
| RT Shadows | Physically correct, soft-edged shadows | Medium – shadows look more natural, especially at edges | Light to moderate |
| RT Global Illumination | Light bouncing between surfaces for realistic ambient lighting | Very high – transforms how indoor and outdoor scenes feel | Heavy |
| RT Ambient Occlusion | Realistic darkening in crevices and corners | Subtle but adds depth | Light |
| Full Path Tracing | All lighting computed via ray tracing with no rasterization shortcuts | Stunning – entire scene is physically accurate | Extremely heavy |
Most current games offer a mix of these effects at different quality settings, letting you choose the balance between visual quality and frame rate that works for your hardware.
The Hardware: RT Cores and GPU Requirements
Real-time ray tracing requires specialized hardware. NVIDIA’s RTX series GPUs include RT cores – dedicated processors designed specifically to accelerate ray-triangle intersection calculations, which is the math at the heart of ray tracing. AMD’s RDNA 2 and RDNA 3 architectures include their own ray accelerators, as does Intel’s Arc lineup.
The reality is that ray tracing performance varies enormously by GPU tier:
- Entry-level GPUs: Can handle light ray tracing effects (RT shadows, RT ambient occlusion) at lower resolutions.
- Mid-range GPUs: Comfortable with RT reflections and some global illumination at 1080p or 1440p.
- High-end GPUs: Capable of full ray tracing or path tracing at high resolutions, especially when combined with AI upscaling.
If you are interested in ray tracing, the GPU is the component that matters most. More VRAM and more RT cores translate directly to better ray tracing performance.
AI Upscaling: The Performance Lifeline
Ray tracing is demanding enough that even powerful GPUs struggle to maintain high frame rates at native resolution with full RT effects enabled. This is where AI upscaling technologies come in – NVIDIA’s DLSS (Deep Learning Super Sampling) and AMD’s FSR (FidelityFX Super Resolution).
These technologies render the game at a lower internal resolution and then use AI algorithms to upscale the image to your display’s native resolution. The result looks remarkably close to native rendering but runs significantly faster – often recovering 50% or more of the performance lost to ray tracing.
In practice, most gamers who enable ray tracing also enable DLSS or FSR. The two technologies are complementary: ray tracing makes the scene look more realistic, and AI upscaling makes it run at playable frame rates. It is hard to recommend one without the other.
Ray Tracing in Practice: What to Expect
When you first toggle ray tracing on in a game that supports it, the difference can range from subtle to jaw-dropping depending on the scene. A rainy city street with RT reflections looks transformative – every puddle reflects the neon signs and passing cars. An indoor scene with RT global illumination gains a warmth and realism that flat, pre-baked lighting simply cannot match.
On the other hand, in a bright outdoor scene with few reflective surfaces, the difference may be harder to notice. Ray tracing shines most in scenes with complex lighting, reflective materials, and dynamic light sources.
The technology is still maturing. Each new generation of GPUs handles ray tracing more efficiently, and game developers are becoming more skilled at implementing it without crippling performance. Full path tracing – where the entire lighting pipeline is ray traced – is the end goal, and a handful of titles already offer it.
Console vs. PC Ray Tracing
Current-generation consoles support ray tracing, but their GPU power is limited compared to high-end PC hardware. Console games typically use lighter RT effects (reflections at reduced resolution, RT shadows) and sometimes offer a choice between a “Performance” mode (higher frame rate, no RT) and a “Quality” mode (lower frame rate, RT enabled). PC gamers with powerful GPUs have more flexibility to enable heavier effects while maintaining smooth performance.
How to Choose
1. Prioritize GPU Power
Ray tracing performance is almost entirely dependent on your GPU. If you want to play with RT effects enabled at reasonable frame rates, invest in a mid-range or higher GPU with dedicated ray tracing hardware. Check benchmarks for the specific games you play – RT performance varies significantly by title.
2. Plan to Use AI Upscaling
If you enable ray tracing, enable DLSS or FSR as well. The visual quality trade-off from AI upscaling is minimal compared to the massive frame rate recovery. Look for a GPU that supports the latest version of DLSS or FSR for the best results.
3. Adjust RT Settings Per Game
You don’t have to run every ray tracing effect at maximum. Start with RT reflections and shadows (the most visually impactful, moderately costly), and add global illumination if your frame rate allows it. Many games let you toggle individual RT effects separately, so experiment until you find the balance that looks great and plays smoothly.
The Bottom Line
Ray tracing brings physically accurate lighting, reflections, and shadows to games – a genuine leap forward in visual quality. It demands a capable GPU and benefits enormously from AI upscaling. Start with moderate RT settings, pair them with DLSS or FSR, and adjust from there. As hardware improves with each generation, ray tracing is quickly moving from a luxury feature to the new standard.