How does terrain work in video games?
A Unity guide explains how video game terrain is built using tiles, heightmaps, voxels, and noise, and how designers shape land to guide player movement and experience.
Video game terrain forms the ground players walk on, influencing mood, movement, and visibility. It can mimic natural surfaces like rock and sand or human-made ground such as cracked pavement. Terrain is not just scenery but a design tool that shapes how players move and what they experience in a game world.
Many 2D games construct worlds from tiles—small, reusable images arranged in a grid to form levels. Tiles define appearance and functionality, marking walkable areas, walls, or obstacles. This approach suits top-down and side-view games, allowing developers to build large maps quickly from a limited set of components.
Most 3D terrain begins with a heightmap, a grayscale image where pixel brightness represents elevation. The game converts a flat grid into hills and valleys by adjusting each point’s height based on the corresponding pixel. Heightmaps are efficient but cannot represent caves or overhangs, as each point can only have one height value.
For terrain requiring caves, overhangs, or destructible ground, some games use voxels—a 3D grid of solid or empty cells. This method enables complex shapes but historically posed technical challenges. Advances such as AI tools like Unity Spark are making voxel terrain more accessible for developers seeking greater flexibility in world design.