heightfield

Heightfield is a data structure used to represent a three-dimensional surface, typically terrain, by storing elevation values on a regular grid. Each grid point corresponds to a sample of height above a reference plane, and the surface is commonly rendered by triangulating adjacent grid cells to form a mesh.

Heightfields are widely used in computer graphics and geographic information systems due to their simplicity and efficient storage. In GIS, the term often overlaps with digital elevation models (DEMs), which are raster grids of elevation data.

Elevation data for a heightfield can be obtained from LiDAR, sonar, photogrammetry, or satellite imagery, or produced procedurally with noise and fractal algorithms. Editing tools allow sculpting, smoothing, and erosion simulation. Interpolation methods, such as bilinear, bicubic, or more advanced splines, determine height values between grid samples when rendering at higher resolutions.

Rendering and performance considerations arise from the regular grid structure. GPU-based rendering and level of detail (LOD) approaches are straightforward for heightfields. Displacement mapping can apply a heightfield to a flat mesh to create a terrain, and lighting often relies on normals derived from the height samples.

Limitations include an inability to represent overhangs or vertical cliffs without additional techniques. The chosen resolution determines fidelity and memory usage, and very large scenes may require tiling, streaming, or multi-resolution representations.

Applications span video games, flight simulators, virtual globes, architectural visualization, and environmental modeling. See also digital elevation model, terrain generation, displacement mapping.