1. A method of mapping movement of objects in a scene, the method comprising: determining, by a processor, a location parameter for each of a plurality of objects at a plurality of points in time; generating a vector field over location and time using the location parameter, to specify, for each object, motion of that object over time; generating a motion path for each object using velocities from the vector field for that object, as the object moves through the scene over time; and outputting a mapping of the motion paths for the plurality of objects.