Voxel

Incremental error rasterisation

Another technique for voxels involves raster graphics where one simply raytraces every pixel of the display into the scene, tracking an error term to determine when to step. A typical implementation will raytrace each pixel of the display starting at the bottom of the screen using what is known as a y-buffer. When a voxel is reached that has a higher y value on the display it is added to the y-buffer overriding the previous value and connected with the previous y-value on the screen interpolating the color values. There is a major downside to voxel rasterization when transformation is applied which causes severe aliasing. The advantage was the ability to rasterise using cheap integer calculations on a CPU without hardware acceleration.^[3]

Outcast, and other 1990s video games employed this graphics technique for effects such as reflection and bump-mapping and usually for terrain rendering. Outcast's graphics engine was mainly a combination of a ray casting (heightmap) engine, used to render the landscape, and a texture mapping polygon engine used to render objects. The "Engine Programming" section of the games credits in the manual has several subsections related to graphics, among them: "Landscape Engine", "Polygon Engine", "Water & Shadows Engine" and "Special effects Engine".^[4] Although Outcast is often cited as a forerunner of voxel technology,^[5] this is somewhat misleading. The game does not actually model three-dimensional volumes of voxels. Instead, it models the ground as a surface, which may be seen as being made up of voxels. The ground is decorated with objects that are modeled using texture-mapped polygons. When Outcast was developed, the term "voxel engine", when applied to computer games, commonly referred to a ray casting engine (for example the VoxelSpace engine). On the engine technology page of the game's website, the landscape engine is also referred to as the "Voxels engine".^[6] The engine is purely software-based; it does not rely on hardware-acceleration via a 3D graphics card.^[7]

John Carmack also experimented with Voxels for the Quake III engine.^[8] One such problem cited by Carmack was the lack of graphics cards designed specifically for such rendering requiring them to be software rendered.

Comanche was also the first commercial flight simulation based on voxel technology. NovaLogic used the proprietary Voxel Space engine developed for the company by Kyle Freeman ^[9](written entirely in Assembly language) to create open landscapes.^[10] This rendering technique allowed for much more detailed and realistic terrain compared to simulations based on vector graphics at that time.^[7]

Gallery

• 
  A (smoothed) rendering of a data set of voxels for a macromolecule

Computer games

• 3D Dot Game Heroes uses voxels to present retro-looking graphics.
• 7 Days to Die is a voxel based open world survival horror game developed by The Fun Pimps Entertainment.
• Ace of Spades used Ken Silverman's Voxlap engine before being rewritten in a bespoke OpenGL engine.
• Amok uses voxels for its environments.^[12]
• Armored Fist 3 is a computer game made by Novalogic that used voxel-based rendering technology.
• Blade Runner is a video game that used voxels to render characters and artifacts.
• Block Ops, a voxel based First Person Shooter game.
• Boundless^[13] is a voxel-based multi-player sandbox game with building elements in connected voxel-worlds that is being developed and published by Wonderstruck Games.^[14]
• Castle Story, a castle building Real Time Strategy game in development, has terrain consisting of smoothed voxels
• Comanche series, a series of computer games made by NovaLogic that used the Voxel Space voxel rasterization for terrain rendering.^[15]
• Command & Conquer: Tiberian Sun, Command & Conquer: Red Alert 2 and Command & Conquer: Yuri's Revenge are computer games made by Westwood Studios that used voxels to render most vehicles.
• Crysis, as well as Cryengine 2 and Cryengine 3, use a combination of heightmaps and voxels for their terrain systems.
• Cube World, an Indie voxel based game with RPG elements.
• Cubiverse a webGL sandbox game crafter, uses voxels for the terrain.
• Delta Force is a computer game made by Novalogic that used the in-house Voxel Space rendering engine.
• Dual Universe is a single-shard universe MMORPG game that uses voxels to build spaceships, civilizations, and space stations.
• EverQuest Next and EverQuest Next: Landmark, upcoming MMORPGs by Sony Online Entertainment, make extensive use of voxels for world creation as well as player generated content
• From the Depths, a voxel-based vehicle building game. Vehicles and structures use voxels for vehicle and structure creation and display.^[16]
• Hexplore, a multi-player role playing game, uses a voxel engine allowing the player to rotate the isometric rendered playfield.
• Master of Orion III uses voxel graphics to render space battles and solar systems. Battles displaying 1000 ships at a time were rendered slowly on computers without hardware graphic acceleration.
• Medieval Engineers is the second voxel-based engineering game by Keen Software House inspired from medieval technology.
• Minecraft is a sandbox video game that uses voxels to store terrain data,^[17] but does not use voxel rendering techniques. Instead it uses polygon rendering to display each voxel as a cubic "block." Minecraft also contains "entities," such as the player and creatures, that exist outside of the voxel data structure.^[18]
• Miner Wars 2081 is a 6DOF open world game made by Keen Software House that uses its own VRage voxel rendering engine to let the user deform the terrain of asteroids allowing tunnels to be formed.
• Outcast, is a third-person action computer game made by former Belgian video game developer Appeal,^[19] with landscapes rendered by a voxel engine.^[20]
• Planet Coaster is a 2016 construction and management simulation developed and published by Frontier Developments which uses a voxel-based terrain editor.^[21]
• Reality Capture LIVE is a volumetric video recording and streaming tool developed by Organic Motion.^[22]
• Resogun is a 2013 voxel-based side-scrolling shoot 'em up video game developed by Finnish developer Housemarque.
• Roblox also uses voxels for terrain.
• Robocraft, a vehicular combat game in which players build combat machines out of voxels and premade components
• ScrumbleShip, a block-building MMO space simulator game in development (as of 2017), renders each in-game component and damage to those components using dozens to thousands of voxels.
• Shadow Warrior and Blood use Build engine for first-person shooter game voxel rendering, instead of sprites, as an option for many of the items pickups and scenery. Duke Nukem 3D has a fan-created pack in a similar style.
• Shattered Steel featured deforming landscapes using voxel technology.
• Sid Meier's Alpha Centauri uses voxel models to render units.
• SkySaga: Infinite Isles is a voxel-based sandbox MMORPG, being developed by Radiant Worlds and published by Smilegate.
• Space Engineers is a voxel-based sandbox game set in space, developed and published by Keen Software House
• StarMade, a voxel-based sandbox game set in space, developed and published by Robin "Schema" Promesberger.
• The Sandbox
• Trove is a voxel-based MMORPG with building elements, developed and published by Trion Worlds.^[23]
• Vangers is a computer game uses voxels for its two-level terrain system.^[24]
• Vox, released in 2012, is a voxel based exploration/RPG game focused on player generated content.
• Vox-L^[25] is a voxel-based video game engine that is being developed and published by Multi-Dimensional Games.^[26]
• Voxatron, a computer game produced by Lexaloffle, is composed and generated fully using voxels.^[27][28]
• Werewolf is a computer game made by Novalogic that used voxel-based rendering technology. It was originally bundled and shipped with the Comanche 2 game although they were two separate games.
• Worms 4: Mayhem uses a voxel-based engine to simulate land deformation similar to the older 2D Worms games.

Voxel editors for games

Many game developers use in-house editors that are not released to the public, but a few games have publicly available editors, some of them created by players.

• Slice based fan-made Voxel Section Editor III for Command & Conquer: Tiberian Sun and Command & Conquer: Red Alert 2.^[29]
• SLAB6 and VoxEd are sculpture based voxel editors used by Voxlap engine games,^[30][31] including Voxelstein 3D and Ace of Spades.
• The official Sandbox 2 editor for CryEngine 2 games (including Crysis) has support for sculpting voxel based terrain.^[32]
• The C4 Engine and editor support multiple detail level (LOD) voxel terrain by implementing the patent-free Transvoxel algorithm.^[33][34]
• Qubicle ^[35] is a simple, professional voxel editor. It has export support to the Unity game engine, as well as many of the more common 3d modeling formats.
• Atomontage Engine is a professional voxel engine also including physics engine.

General purpose voxel editors

There are a few voxel editors available that are not tied to specific games or engines. They can be used as alternatives or complements to traditional 3D vector modeling.