Have you ever seen images that look very realistic that are generated on a computer? Or have you watched the latest trailer for a game with a feature called 'ray tracing', making shadows and light look incredibly realistic? In 3D computer graphics, there is a tool called ray tracing which can enhance the way images look by tracing the path of light using rays, and simulating how it interacts with other objects.
Image from: https://www.wired.com/story/what-is-ray-tracing/
The History of Ray Tracing
Ray tracing has been mentioned from times as early as the 16th century by Albrecht Durer, who is credited as the inventor of ray tracing. In a book that he wrote, he described how he could use a thread to form a ray and a hook on the wall acts as the center of projection, which is like the camera position in ray tracing. Ray tracing was relatively slow, and was usually used for still images, but now, it can be used in more applications thanks to more powerful graphics processing units, known as GPUs.
How Does it Work?
Ray tracing shoots rays from a light source, and when they hit surfaces, they are reflected. This light can interact with multiple different variables in the environment, which can change the color of the light, for example. The light is continually traced until it is no longer in the scene.
Taxing on Graphics Processors
While ray tracing may sound simple, it is very taxing on the processors in your system, meaning that if you were to play a game using that method, it would look very choppy. So, a solution was made, that uses something called reciprocity, which means a the inverse of a light beam works like the original to cast rays from the theoretical camera into the scene. Therefore, only the rays which affect the scenery that you are seeing in a game are cast, which allows for it to run faster. The reflections can also be limited if the light contribution is too small to make a difference.
What Can You Do With Ray Tracing?
With ray tracing, you can do many things, including making realistic looking 3D renders in applications like Blender, and you can also make ray-traced animations, that look very real thanks to the accurate lighting and reflections. These animations can either be pre-rendered, which allows for more features of ray tracing to be included in the video, or, thanks to recent innovations, these calculations can be done in real-time. The render will be simpler in real-time, but still look very realistic. However, if you do not have a high performance computer, it would be difficult to do renders. Something that is becoming more accessible is ray-traced gaming. Popular titles like Fortnite and Minecraft are using this technology to make shadows, reflections, and lighting look more realistic.
Why is it Not Mainstream Yet?
Until about 2 years ago, using ray tracing in games was merely a dream. However, thanks to a company called Nvidia, who creates powerful GPUs for gaming and workstations, they introduced a new technique that allowed for real-time ray tracing. Another GPU maker called AMD followed this year with their own ray tracing GPU, which can be found inside high performance gaming PC's, the new Xbox, and the new PS5. While this is a huge step towards ray tracing becoming more mainstream, don't expect phones and tablets to get these features anytime soon, because one thing high-performance graphics processors produce is heat. A tablet's cooling system simply cannot handle the heat produced by a high power GPU yet.
Additional Advice
If you would like to try ray tracing for yourself in games, you can buy the PlayStation 5 from Sony, or the Xbox Series X or S from Microsoft. If you want a machine that can both ray trace in games and that can be used for renders, you can either buy a pre-built computer with an RTX graphics card or an RX6000 series graphics card, or build your own computer!
Written by Overclocked RGB
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