In short, the patch contains a couple of interfaces and classes to support the following:
- An extension of the XYZDataset that can handle multiple z-coordinates.
- A new renderer that can act similarly to both an XYBlockRenderer and an XYBubbleRenderer and that can handle multiple z-coordinates.
- A ZRangeLegend thatt can act as a PaintScaleLegend but that can also display other way of visualizing a value range and that will remain consistent with the z-range of a its assigned dataset and with the rendering properties of its assigned renderer.
Details see this thread: http://www.jfree.org/phpBB2/viewtopic.php?f=3&t=27864