1. A method of arranging objects within a three-dimensional virtual space, the method being performed on a virtual worlds service provider, the method comprising: maintaining, on a virtual worlds service provider comprising one or more computer processors, an instance of a virtual world scene comprising a plurality of objects in a first spatial arrangement; identifying a first non-player object of the plurality of objects, the first non-player object having a first spatial position; receiving an original spatial position for the first non-player object, the original spatial position identifying a default position to which the first non-player object is to be returned to within the virtual world scene across a plurality of instances of the virtual world scene, the plurality of instances including the maintained instance; comparing the first spatial position of the first non-player object to the original spatial position of the first non-player object, said comparing including determining a distance between the first spatial position and the original spatial position; computing a transition path for replacing the first non-player object from the first spatial position to the original spatial position, based on the comparison of the first spatial position of the first non-player object and the original spatial position; and automatically transitioning the first object based on the computed transition path.