Note that, despite the name, world space does not imply that users have to store their actual world representation in this coordinate space. For example, flight simulators often have to transform their planet-scale world representation to an aircraft relative representation for rendering to work around the issues inherent in rendering extremely large scenes. The basic issue is that the relatively low level of floating point precision available on current graphics hardware means that if the coordinates of objects within the flight simulator's world were to be used directly, the values would tend to be drastically larger than those that could be expressed by the available limited-precision floating point types on the GPU. Instead, simulators often transform the locations of objects in their worlds such that the aircraft is placed at the origin (0, 0, 0) and the objects are positioned relative to the aircraft before being passed to the GPU for rendering. As a concrete example, within the simulator's world, the aircraft may be at (1882838.3, 450.0, 5892309.0), and a control tower nearby may be at (1883838.5, 0.0, 5892809.0). These coordinate values would be far too large to pass to the GPU if a reasonable level of precision is required, but if the current aircraft location is subtracted from all positions, the coordinates in aircraft relative space of the aircraft become (0, 0, 0) and the coordinates of the tower become (1883838.5 - 1882838.3, 0.0 - 450.0, 5892809.0 - 5892309.0) = (1000.19, -450.0, 500.0). The aircraft relative space coordinates are certainly small enough to be given to the GPU directly without risking imprecision issues, and therefore the simulator would essentially treat aircraft relative space and r2 world space as equivalent .