Why Ray Tracing in Games Is Huge
Since the unveiling of Nvidia’s RTX 2070 and 2080 cards a couple weeks ago, I’ve started to hear a lot of chatter that’s pretty dismissive of the technology. While I’m not sure this first gen is going to be the thing that will convert people, or whether the pricing Nvidia has gone with makes sense for the market, I think people are underplaying just how big ray tracing is. This tech, more than almost any graphics tech since we started using dedicated 3D acceleration cards to play Quake, has the potential to change how games are developed and played.
If you’ve followed our coverage of the RTX cards, you might already be familiar with just what ray tracing is, but let’s lay the definition out here to make sure we’re all talking about the same thing.
Ray tracing isn’t just another step in adding more flash to games. It’s a basic aspect of 3D rendering tech that has been a sort of holy grail for game development for decades. Ray tracing is the act of tracing rays of light through a 3D-rendered scene to accurately follow light rays in that scene. This affects not just lighting but reflections as well. Movie studios have been using this for years. When you hear Pixar talk about Toy Story taking thousands of hours to render, ray tracing is why. Any time you introduce light into a 3D scene, you can go about rendering that light in a couple different ways. You can ray trace it, which involves tracking billions of rays of light to see where they go and then rendering things with that. Or you can simulate it with some tricks.
For example, let’s say you have a room with a table and a window, with a glass vase on the table. Sun is streaming in through the window. You can see in your head how it would all play out in real life, right? When you open the window, even though the light is only coming in through this box on the wall, the whole room lights up because light bounces. If you have a white tile floor and bright white walls, the room will light up one way, while a David Lynchian combination of earth tones and rough materials would stifle the light. Light filters through the glass vase, drawing a distorted version of the vase on the table. If the vase is full of water, the light will bend differently, while flowers will create their own silhouettes on the table if the light is right.
Right now, if you want to create this room in a game, you have to basically do a bunch of small magic tricks to make the whole magic trick work. You have to put in that main light source, of course, but then you have to put in smaller, invisible light sources to simulate where the light might bounce and make the space visible. You have to put in invisible texture maps that tell reflective items what reflections to show when you look at them. And further, you have to decide what stuff to “cull†or cut out of the scene, because modern graphics cards can’t handle rendering the whole world around us.
Article source: https://www.technobuffalo.com/2018/09/06/why-ray-tracing-in-games-is-huge/