What is Ray Tracing?

Ray tracing is a technique for modeling 3D digital graphics that simulates light’s behavior for more realistic reflections. It does so by using algorithms that force light to bounce off reflective surfaces as in real life.

Table Of Contents

    How Ray Tracing Works

    Birch planks and glass stacked perpendicular to each other in order to show off how light bounces off of each surface with a ray tracing mod.

    To understand how ray tracing works, you need to comprehend the different parts of the game that its algorithms use:

    • Camera: this is your point of view as the player, which exists on the opposite side of the image plane from all the in-game elements
    • View Rays: these are the direct lines of vision that extend from the camera through the image plane and into the in-game world
    • Image Plane (Virtual Screen): this is the vertical grid of pixels through which view rays travel when going from the camera to the in-game world
    • Scene Objects: these are the physical objects that light bounces off
    • Shadow Rays: these are the indirect lines of vision that extend between scene objects and sources of light
    • Light Sources: these are the origins of the light being created in a game

    What the Algorithm Does to Make Beautiful Visuals

    Now that you know the parts the algorithm looks at, you can figure out how they work together to create stunning visuals in video games. Though, keep in mind that this process works a bit differently than how your eyes perceive light in real life. The ray tracing algorithm begins from the camera and works outward towards the light source—the opposite of how vision works outside of 3D graphics.

    Firstly, the camera generates view rays that pass through the image plane. The pixels of the image plane that the view rays pass through register on the game’s algorithm. This determines the angle at which you see light. Next, the view rays get a bit chaotic. They start hitting all scene objects currently in the player’s field of view.

    When this happens, the view rays turn into shadow rays. The shadow rays then seek out the nearest light sources and head directly to them. This completes the journey of your visual lines via view rays and shadow rays.

    This process happens many times during every frame of animation. As such, it gives your eyes the impression of seeing reflections similarly to how you would see them in real life: with tons of minute refractions.

    Games That Have Ray Tracing

    A player riding through a shallow lake at dawn.

    Only modern and upcoming titles will have ray tracing as a feature. Up until recently, graphic-generating programs couldn’t quite render this complex level of light transport as quickly as other types of visuals.

    However, since 2018, the software and hardware of graphics cards have become robust enough to allow ray tracing to be a common feature in video games. Prior to this, ray tracing was only really viable in still images, movies, and TV shows due to the slow render time.

    In addition to the games that officially have ray tracing as a feature, there are some that can only get it through hacking or modding.

    Current Games With Ray Tracing

    • A Plague Tale: Requiem
    • Amid Evil
    • Battlefield V
    • Battlefield 2042
    • Bright Memory & Bright Memory: Infinite
    • Call Of Duty: Black Ops Cold War
    • Call of Duty: Modern Warfare (2019)
    • Chernobylite
    • Chorus
    • Control
    • Crysis Remastered & Crysis Remastered Trilogy
    • Cyberpunk 2077
    • Deathloop
    • Deliver Us The Moon
    • Dirt 5
    • Doom Eternal
    • Dying Light 2
    • Elden Ring
    • Everspace 2
    • F1 2021
    • F1 22
    • Far Cry 6
    • FIST: Forged In Shadow Torch
    • Five Nights At Freddy’s: Security Breach
    • Fortnite
    • Forza Horizon 5
    • Ghostrunner
    • Ghostwire: Tokyo
    • Gotham Knights
    • Godfall
    • Hell Pie
    • Hitman 3
    • Industria
    • Icarus
    • Jurassic World Evolution 2
    • Justice
    • JX Online 3
    • Lego: Builder’s Journey
    • Loopmancer
    • Martha is Dead
    • Marvel’s Guardians of the Galaxy
    • Marvel’s Spider-Man Remastered
    • Mechwarrior V: Mercenaries
    • Metro Exodus
    • Minecraft
    • Moonlight Blade
    • Mortal Shell
    • Myst
    • Observer: System Redux
    • Paradise Killer
    • Pumpkin Jack
    • Quake II RTX
    • Resident Evil 2
    • Resident Evil 3
    • Resident Evil 7
    • Resident Evil Village
    • Raji: An Ancient Epic
    • Ring Of Elysium
    • Sackboy: A Big Adventure
    • Saints Row
    • Severed Steel
    • Shadow of the Tomb Raider
    • Stay in the Light
    • Steelrising
    • Sword and Fairy 7
    • The Ascent
    • The Fabled Woods
    • The Medium
    • The Persistence
    • The Riftbreaker
    • Watch Dogs Legion
    • Wolfenstein: Youngblood
    • World Of Warcraft: Shadowlands
    • Wrench
    • Xuan-Yuan Sword VII

    (Some) Upcoming Games With Ray Tracing

    • Atomic Heart
    • Avatar: Frontiers Of Pandora
    • Boundary
    • Dying: 1983
    • Forza Motorsport
    • Halo Infinite
    • Layers of Fears
    • Marvel’s Spider-Man: Miles Morales
    • Mortal Online 2
    • Portal with RTX
    • Ratten Reich
    • Ready Or Not
    • Skull and Bones
    • STALKER 2: Heart of Chornobyl
    • Star Wars Jedi: Survivor
    • Synced: Off-Planet
    • The Day Before
    • The Lord of the Rings: Gollum
    • The Witcher III: Wild Hunt – Game of the Year Edition
    • Turbo Sloths
    • Vampire: The Masquerade – Bloodlines 2
    • Voidtrain
    • Warhammer 40,000: Darktide
    Showing the difference between ray tracing in the game Watch Dogs being inactive (left) and active (right). On the right, the reflections in the water are more realistic.