Heightmap
From Wikipedia, the free encyclopedia
In computer graphics, a heightmap or heightfield is a raster image used to store values, such as surface elevation data, for display in 3D computer graphics. A heightmap can be used in bump mapping to calculate where this 3D data would create shadow in a material, in displacement mapping to displace the actual geometric position of points over the textured surface, or for terrain where the heightmap is converted into a 3D mesh.
A heightmap contains one channel interpreted as a distance of displacement or “height” from the “floor” of a surface and sometimes visualized as luma of a grayscale image, with black representing minimum height and white representing maximum height. When the map is rendered, the designer can specify the amount of displacement for each unit of the height channel, which corresponds to the “contrast” of the image. Heightmaps can be stored by themselves in existing grayscale image formats, with or without specialized metadata, or in specialized file formats such as Daylon Leveller, GenesisIV and Terragen documents.
Heightmaps are commonly used in geographic information systems, where they are called digital elevation models.
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[edit] Programs that use heightmaps
Heightmaps are widely used in terrain rendering software and modern video games. Here they are sometimes called “terrain objects” because they are so commonly used to model terrain. In the earliest games using software rendering, the elements often represented heights of columns of voxels rendered with ray casting. In most newer games, the elements represent the height coordinate of polygons in a mesh.
[edit] Rendering software
- Terragen – terrain renderer
- MegaTerrain - a devkit for real-time terrain rendering
[edit] Generating software
- LandCraft – online Flash 8 terrain generator
- terraineer – a small tool generating and teaching heightmap generation
- Landscape Studio – a free Java-based suite providing complex heightmap generation
- World Machine – a procedural terrain generator, which can simulate natural erosion. A free version is available with restriction only in the size of terrain generated(512*512)
- Nem's Mega 3D Terrain Generator – A 100% free generator which gives the user the ability to move the terrain freehand rather than by changing the settings on tools.
- Grome Editor – Professional terrain editor for game development and 3D simulations from Quad Software.
[edit] Computer and video games
Many 3D computer and video games use heightmaps to store and generate terrain data. Benefits of such a system include ease of implementation as well as modding. Players can easily generate their own heightmaps for use within the game using widely available software. Heightmaps are usually complemented by texture maps that are then applied to the terrain in-game for extra detail and realism.
- NovaLogic's Comanche series – first popular computer game to use heightmap terrain, advertised as a “Voxel Space” engine
- Battlefield 1942 and Battlefield 2 use heightmaps generated using Terragen and modified in the respective editors.
- Crysis's Sandbox editor
- Far Cry level editor – level editor that imports heightmaps
- GenSurf – A mapping tool for Quake 3 Arena to make realistic heightmap terrain
- Neverwinter Nights 2 – The Electron toolset can be used to create heightmaps, while the Electron engine is used to traverse them
- OpenTTD scenery editor
- Myth
- Outcast
- Sauerbraten
- Spring – Open source 3D RTS engine
- Terra Nova: Strike Force Centauri
- SimCity Societies – Expected to use height maps for terrain generation.
- Crashday – Uses Heightmaps in its Track Editor. Custom maps can also be imported by copying them into the heightmap folder.
