autotiling

Autotiling is a technique used in tile-based graphics and level design to automatically select and arrange tiles according to the configuration of neighboring tiles. The aim is to create seamless transitions between terrain types or features (for example grass meeting water, or dirt transitioning to a path) without manually drawing every tile variant.

Most autotiling systems assign each map cell a tile type and then examine the surrounding eight cells. A code or bitmask representing which neighbors share the same type or require a transition is computed. This code selects a corresponding tile variant from a predefined sprite sheet or tile set that includes the necessary edge, corner, and junction graphics. Some systems support multiple layers or rules for complex transitions, such as shoreline blending or road connectivity.

Common applications are in 2D games, level editors, and procedural map generation. Autotiling reduces art requirements, speeds map creation, and allows larger, cohesive maps by reusing a compact set of tile art.

Variations include bitmask-based autotiling and rule-based or connected-texture approaches. Strengths include consistency and efficiency; limitations include dependence on well-designed tile sets and potential artifacts at borders or under certain neighbor configurations, which may require manual adjustments or handcrafted tiles.