Ray tracing: Everything you need to know about ray tracing

Ray tracing is one of the hottest topics of 2019. Not only will Nvidia’s new RTX graphics cards support the technology, but so will the upcoming PS5 and Xbox 2.

But what exactly is ray tracing? We explain the groundbreaking light-rendering technology here, while also explaining how it will improve the visuals for future games to come.

And if you want to start gawping at ray tracing games right now, we detail the hardware you need to get it up and running as well was which games support it. Read on for everything you need to know about ray tracing.

Related: Best graphics cards 2019 

What is ray tracing?

Ray tracing is a rendering technique that creates more realistic light effects. By using ray tracing tech to simulate the physical behaviour of light, you’ll see it bounce off objects in the virtual world just as it would in reality.

While ray tracing has been around for some time in the film and TV production worlds, the release of Nvidia’s RTX graphics cards marked the first instance when ray tracing could be rendered in real-time,  making it possible to incorporate into video games.

Nvidia Ray Tracing Shadow of the Tomb Raider

Nvidia’s screenshot of Shadow of the Tomb Raider demonstrating ray tracing

It isn’t only light that benefits from ray tracing; this more realistic behaviour of light also creates more authentic reflections and shadows.

Look down at a puddle, and ray tracing should allow you to see your character’s face staring right back at you. While reflections are nothing new in video games, developers previously had to pre-render them. Clever tricks, such as rendering an identical room on the other side of a mirror, created the illusion of a reflection, but real-time ray tracing makes the real deal possible. 

Shadows, meanwhile, will look more dynamic. Think of a rising sun over a forest. With ray tracing, shadows are directly affected by the light source and will move accordingly with the sun’s position in the sky. The Shadow of the Tomb Raider tech demo also depicted how flickering firecrackers and candles will create more realistic and atmospheric lighting in dark environments.

Ray tracing games

The full list of games confirmed to support ray tracing is as follows:

However, most of these games are still awaiting software patches before they can feature ray tracing. So far, Battlefield 5, Shadow of the Tomb Radier and Metro Exodus are among the few video game to have the technology activated right now.

Even more games are expected to confirm support for ray tracing throughout 2019. And now the PS5 and Xbox 2 are confirmed to be supporting ray tracing, it’s likely that developers will be much more keen to start using it.

We’ll revise this list as soon as more information becomes available.

Related: Best PC Games

Is ray tracing worth it?

Nvidia’s ray tracing tech demos may look impressive, but how good is the technology in action? We tested real-time ray tracing for ourselves with Battlefield 5 – the very first game to actively support the technology.

In the snow-blanketed landscapes of Battlefield 5’s single player experience Nordlys, ray tracing truly excelled. Mountain ranges could be seen in the reflection of a frozen lake, while flames glinted off the metallic surface of machine guns, even as snow thundered down.

On left: DXR turned off. On right: DXR turned on

Explore one of the many deserted homes in Battlefield 5, and the ray tracing improvements are even more noticeable. Glass cabinets show a clear reflection of the entire room, as well as your own character. If a sneaky solider were to sneak up behind you while you ogled the cabinet, you’d be able to spot them immediately. Turn off DirectX Raytracing (DXR) and the glass cabinet will still show a reflection, but a very blurred and murky one that has been pre-designed and can’t be affected by its surroundings, no matter how hard you attempt to intercept the light.

Even the glass-fronted picture frames hanging up on the walls benefit significantly from ray tracing. Once activated, you’re able to see the sunlight glistening on the surface, giving it a glossy appearance rather than the dull image you’d usually find.

On left: DXR turned off. On right: DXR turned on

But while this level of detail is incredibly impressive, it’s so subtle you probably wouldn’t notice it unless you went looking for it, especially in fast-paced bombastic ventures such as Battlefield 5 where you’re too busy gunning down Nazis to bother gazing at a reflection in a cabinet.

When you factor in how much of a performance drain that ray tracing is on the GPU, you have to ask yourself whether that subtle improvement is worth it. Playing through the Nordlys level on Battlefield V in Full HD with DXR turned off, the game held an approximate frame rate average of 130fps. After activating DXR, though, that frame rate average dropped to 80fps. That’s a whopping 50fps difference.

Since we were using the Alienware Aurora R8 gaming desktop with a Nvidia GeForce RTX 2080 Ti and Intel Core i9 9900K configuration, Battlefield V still ran smoothly despite the 50fps hit. If you’re using a less modest graphics card though, (such as the RTX 2070 or GTX 2080,) or you fancy playing in 4K rather than Full HD, then frame rates might drop to such a degree that you may decide to sacrifice DXR altogether.

Related: Battlefield V Review

What do I need for ray tracing?

Right now, there’s actually a great deal of graphics cards that technically support ray tracing. Nvidia recently released a patch enabling support on all GTX graphics cards. That said, you currently won’t get the full benefit of the technology unless one of Nvidia’s RTX cards.

The consumer cards currently in the RTX lineup include the RTX 2080 Ti, RTX 2080, RTX 2070 and RTX 2060 GPUs.

These graphics cards boast new hardware called Tensor Cores and RT Cores, which are required to make real-time ray tracing work as efficiently as possible. Nvidia also invented the term ‘Giga Rays’, as a measurement of performance for ray tracing.

Nvidia says that 5 Giga Rays per second is the minimum amount of virtual light ideally required to fully illuminate a typical room in a video game environment. The RTX 2070 offers the standard 5 Giga Rays/sec, while the 2080 offers 8 Giga Rays/sec and the 2080 Ti a whopping 10 Giga Rays/sec.

In other words, lighting effects on games played on a system with a 2080 Ti running will look the most impressive, realistic and immersive. 

It looks like AMD will soon be joining the ray tracing party too, with the next-gen AMD Navi 7nm architecture strongly rumoured to be supporting the technology. The PlayStation 5 will also feature ray tracing, using the AMD Navi GPU architecture, but the next-gen console isn’t expected until 2020.

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