In a data visualization system, a method of graphically representing discrete data as a continuous surface in image space, the method comprising the steps of: a data retrieval module retrieving discrete data from a data storage device in communication with the data visualization system; an interpolation module calculating a first set of values for a weighted interpolation function based on the retrieved discrete data; a smoothing module calculating a second set of values for one or more weighted approximation functions based on the retrieved discrete data; and a surface combining module combining the first and second set of calculated values over the image space to graphically represent a continuous surface.