| 摘要 |
A method of watermarking video images of a particular instance of a virtual environment comprises the steps of selecting a plurality of virtual objects for inclusion within the virtual environment, respectively altering a physical property of the selected virtual objects from a reference value to a respective different value (wherein the respective different value is selected responsive to respective identification values of identification data associated with that particular instance of the virtual environment, and wherein the physical property has a visible effect on the appearance of the virtual objects), and rendering for display the virtual environment comprising the altered virtual objects. |
