A computer-readable storage medium that includes a computer program and corresponding method, the program comprising code which will: generate a computer-modelled environment comprising a three-dimensional computer-modelled space and one or more three-dimensional computer-modelled objects within that space; and generate a map of values of a kinetic parameter over the object's surface, the kinetic parameter parameterizing a kinetic activity to be modelled to occur within the computer-modelled space in relation to that surface.