Introduction
Raytracing is a powerful rendering technique that can produce incredibly realistic graphics by simulating the physical behavior of light. With dedicated raytracing hardware now available on desktop GPUs, raytraced games are becoming more common on PCs and consoles. But can mobile raytracing take phone games to the next level visually? Let’s dive in and find out.
What is Raytracing?
Raytracing simulates how light beams interact with surfaces in a 3D scene. It works by tracing the path of light rays as they bounce around the scene, calculating how they interact with objects via reflections, refractions, and shadows. This allows raytracing to realistically simulate complex optical effects like reflections in mirrors, refractions through glass, shadows, ambient occlusion, depth of field, and global illumination.
Raytracing produces images that are far more realistic than what traditional rasterization techniques can achieve. Rasterization uses shortcuts to fake lighting effects rather than simulating light rays. This means rasterized graphics lack the realism of raytraced images. However, rasterization is much less computationally demanding than raytracing.
Raytracing on Desktops vs Phones
Desktop GPUs from Nvidia and AMD now have dedicated raytracing cores to accelerate raytracing workloads. Games like Control, Metro Exodus and Minecraft with raytracing show how much more realistic lighting can become with raytracing.
But raytracing requires serious compute power – something mobile phones lack compared to desktop GPUs. For example, Nvidia’s RTX 3080 desktop GPU has 10,496 CUDA cores and can do 29 TFLOPS of compute. By comparison, Qualcomm’s new Snapdragon 8 Gen 1 mobile chip has an Adreno GPU with just 768 cores and 3.2 TFLOPS performance.
The massive difference in cores and compute power is why real-time raytracing has not been feasible on phones until now. Very simple raytraced effects were introduced on phones using hybrid rendering techniques that combined rasterization with raytracing. But dedicated hardware is needed to raytrace complex scenes in real-time while achieving playable frame rates.
Hardware Raytracing Comes to Phones
In 2022, the first mobile GPUs with dedicated raytracing cores are arriving – the Adreno GPU inside Snapdragon 8 Gen 1 and the Mali GPU in MediaTek’s Dimensity 9000. These chips have 1-2 raytracing cores alongside the traditional graphics cores. While not as powerful as desktop RT cores, it’s a start.
ARM’s raytracing cores in these chips focus on a technique called screen-space raytracing. This raytraces only the pixels currently on the screen rather than the entire 3D scene. This localized approach reduces computational load and makes real-time raytracing on phones feasible today.
Raytraced Graphics Coming to Mobile Games
Dedicated raytracing hardware unlocks the ability for mobile games to use raytracing for more realistic real-time graphics. Here are some raytraced effects that will be possible on phones now:
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Reflections – Raytraced screen-space reflections in glossy surfaces like wet streets, cars, marble floors etc. This can greatly enhance visuals.
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Shadows – Raytraced shadows with correct penumbra effects depending on light angle and distance.
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Ambient occlusion – Raytraced ambient occlusion adds contact shadows in small gaps and crevices.
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Global illumination – Raytraced global illumination simulates indirect bounced lighting for more realistic environments.
These raytraced effects can take mobile gaming graphics to a whole new level visually. Of course, the limited raytracing power on phones means simpler scenes compared to PC/console raytracing. But some mobile games should be able to achieve graphics approaching current-gen console quality with raytracing.
What Games Will Get Raytracing?
Popular mobile game engines like Unity and Unreal Engine are adding support for raytracing. This will make it easier for mobile game developers to add raytraced effects to their games.
Some mobile games that could showcase raytracing include:
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PUBG: New State – Raytraced reflections and shadows could enhance the visuals in this popular battle royale shooter.
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Genshin Impact – The anime-style open world of Genshin Impact could become even more gorgeous with raytraced global illumination and shadows.
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Call of Duty: Mobile – Raytraced graphics would increase realism in CoD Mobile’s multiplayer maps and modes.
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Asphalt 9: Legends – Raytraced car reflections and neon lighting effects could make this racing game shine.
Of course, not all games will opt for raytracing due to the performance costs. But expect some graphically demanding titles to embrace raytracing to stand out visually.
Raytracing Performance on Phones
The biggest challenge with raytracing on phones will be delivering smooth frame rates with acceptable battery drain. Early indications are that performance will be in the 30-60 FPS range at 720p-1080p resolution when raytracing is enabled.
Dedicated raytracing cores allow screen-space raytracing to be executed efficiently without hammering the normal graphics cores. But some slowdowns are inevitable, so developers will likely use raytracing selectively or include options to disable it. Lower resolutions like 720p also help improve raytracing performance on phones.
As expected, raytracing does drain battery life faster due to the increased computational workload. However, for short gaming sessions, the battery hit may be acceptable, especially as mobile chipsets become more efficient.
The Road Ahead for Mobile Raytracing
While still early days, dedicated raytracing hardware has opened the door for raytraced graphics to bring a new level of realism to mobile gaming. As raytracing cores improve in future generations of mobile chipsets, the performance and quality of raytraced games will keep increasing.
By simulating realistic light and shadows, raytracing can provide levels of graphical fidelity not possible with only rasterization. This is an exciting development for the future of mobile gaming graphics. Though still limited compared to desktop raytracing, mobile raytracing should let some phone games start rivaling console-quality visuals soon.
Conclusion
Raytracing’s arrival on phones heralds a new era for mobile gaming graphics. Dedicated raytracing hardware like ARM’s raytracing cores in Snapdragon 8 Gen 1 and Dimensity 9000 finally make real-time raytracing feasible on phones. While performance is still limited compared to desktop raytracing, we should see the first mobile games with raytraced graphics that increase realism via realistic shadows, reflections, lighting and more. As mobile raytracing matures, it can help elevate phone gaming visuals closer to console-quality graphics.
