Abstract: A data processing system includes a rendering system adapted to process data objects to render display frames for presentation via a visual display screen. The display frames include 2D display items corresponding to the data objects, each display item having a 2D screen location within the display frame defined by reference to an X/Y display plane. The rendering system renders stereoscopic 3D views of display frames by rendering left- and right-eye views of the display frames. The left- and right-eye views of the display frames are rendered by processing the data objects corresponding to the 2D display items such that respective left- and right-eye copies of the 2D display items are included in the left- and right-eye views. A set of 3D effects rules is provided that specify relationships between stereoscopic 3D effects and parameters associated with the data objects corresponding to the 2D display items.