Abstract: Method for improving the quality of a set of a three dimensional (3D) point cloud data representing a physical surface by detecting and filling null spaces (606). The method includes analyzing (206) the data to identify the presence of a plurality of level 1 fractals (401), each defined by a plurality of voxels (400) containing data points arranged in one of a plurality of three-dimensional patterns. The method also includes selectively filling (212) voxels in the 3D point cloud data with a first predetermined limited number of data points to increase a number of instances where level 2 fractals (604) can be used for representing the 3D point cloud data. Each level 2 fractal is defined as a common plurality of the level 1 fractals having a common three-dimensional pattern, where the common plurality of level 1 fractals are also arranged in accordance with the common three dimensional pattern.