A virtual reality, VR, system comprising a motion system for moving objects in a virtual reality space, the system comprising: a motion system controller; a modular floor comprising a plurality of tile assemblies defining a support surface for a first and a second different object; a position monitoring assembly configured to provide position information for the first object and the second object within the virtual reality space; wherein each of the tile assemblies comprises a planar tile with an upper surface for supporting the first and second objects and a drive system, and wherein the motion system controller generates control signals, based on position information for the first and second objects from the position monitoring assembly and a predicted travel path for each of the first and second objects, to independently control operation of the tile assemblies of the modular floor to move the first and second objects on the support surface, characterized in that the drive system comprises a vibration-inducing assembly operable to oscillate the planar tile in a horizontal plane and with a preferential friction assembly operable to selectively reduce friction between the upper surface and any of the first object and the second object supported upon the upper surface and the motion system controller being configured to independently operate the tile assemblies to impart a first motion to the first object and a second motion differing from the first motion to the second object, wherein the first and second motions are away from other objects or are for the first object away from the second object and for the second object away from the first object, the independent operation comprising assigning first and second sets of the tile assemblies to each of the first and second objects, respectively to impart the first and second motions; and wherein the preferential friction assembly comprises at least one of: a plurality of ultrasonic transducers positioned on the upper surface of the planar tile; an array of ultrasonic transducers provided on or in the first and second objects. a motion system controller; a modular floor comprising a plurality of tile assemblies defining a support surface for a first and a second different object; a position monitoring assembly configured to provide position information for the first object and the second object within the virtual reality space; wherein each of the tile assemblies comprises a planar tile with an upper surface for supporting the first and second objects and a drive system, and wherein the motion system controller generates control signals, based on position information for the first and second objects from the position monitoring assembly and a predicted travel path for each of the first and second objects, to independently control operation of the tile assemblies of the modular floor to move the first and second objects on the support surface, characterized in that the drive system comprises a vibration-inducing assembly operable to oscillate the planar tile in a horizontal plane and with a preferential friction assembly operable to selectively reduce friction between the upper surface and any of the first object and the second object supported upon the upper surface and the motion system controller being configured to independently operate the tile assemblies to impart a first motion to the first object and a second motion differing from the first motion to the second object, wherein the first and second motions are away from other objects or are for the first object away from the second object and for the second object away from the first object, the independent operation comprising assigning first and second sets of the tile assemblies to each of the first and second objects, respectively to impart the first and second motions; and wherein the preferential friction assembly comprises at least one of: a plurality of ultrasonic transducers positioned on the upper surface of the planar tile; an array of ultrasonic transducers provided on or in the first and second objects. a plurality of ultrasonic transducers positioned on the upper surface of the planar tile; an array of ultrasonic transducers provided on or in the first and second objects.