Roblox Raycasting

In the Roblox Engine, raycasting is the act of casting a Ray from a point in 3d space (represented as Vector3) in a given direction (also represented as Vector3) to detect if a Part or Terrain cell is hit by the ray. It has many use cases from building guns & other projectile weapons; to detecting terrain beneath a player's feet as they walk.

Roblox named it after the concept of Raycasting in computer graphics.