This article explains how ray tracing makes the difference.
What is Ray Tracing?
Ray tracing is a technique forrenderingcomputer graphics that creates an image by tracing rays' path through a scene.
CD Projekt Red
How Ray Tracing Works
Ray tracing emulates real-world lighting.
The light we see is the result of photons emitted from energy sources, like the sun.
Photons can bounce and scatter as they collide with objects.
Nvidia
A mirror is all you better see this in action.
Light hitting a mirror creates a reflection.
Ray tracing simulates this.
Nvidia
Modern games trace somewhere between one and four rays per pixel.
Still, that’s enough to simulate the real world.
CD Projekt Red
Tracing the path of a ray also lets it interact with the game world.
Ray tracing is a significant step forward for 3D graphics.
It creates a realistic image by simulating the path of rays as they move through a game.
This leads to lighting that can interact with the environment even when the environment isnt visible to the player.
Ray Tracing vs. Rasterization
You may still be confused even if you understand this explanation.
Reflections were present in past games, even those now several decades old.
How is ray tracing different?
Past 3D games, and most modern games, use rasterization.
Rasterization combines the elements of a 3D game world visible to the player into a 2D image.
However, this creates a problem.
Nvidia
Lets return to the example of a mirror.
With rasterization, theres nothing for the mirror to reflect.
Of course, mirrors exist in modern games.
They render the scene twice.
One pass is from the players point of view, while another is from a different perspective.
That doubles the performance needed to render a scene, however.
Screen space reflections, a technique in popular 3D game engines, use on-screen data to create a reflection.
This technique is ideal for reflective surfaces at an angle to the players perspective, such as water.
However, reflected objects disappear if the item reflected moves off-screen.
Ray tracing doesnt share these problems because, unlike rasterization, it can trace outside the player’s perspective.
What Hardware Does Ray Tracing Require?
Unfortunately, they took hours to render.
A video game needs real-time ray tracing at 30 frames per second or higher.
Thats only possible with a video card designed to accelerate ray tracing.
Nvidias RTX ray tracing relies on silicon called a Tensor Core.
Tensor Cores are only found in RTX video cards.
However, performance is abysmal compared to RTX cards.
AMD cards that accelerate ray tracing dont have specific branding and dont have dedicated silicon.
Instead, they use hardware tweaks and software updates for better results.
Its more difficult to identify AMD cards that accelerate ray tracing, so pay attention to the details.
SonysPlayStation 5and Xbox Series X and S have graphics hardware from AMD that can accelerate ray tracing.
Its up to developers to enable, however, and many games dont.
