1. A method for obtaining data, from a data set that describes the topography of a three-dimensional surface at points, at a resolution appropriate for visualization on a display screen of an electronic device, comprising: organizing data of the data set into a number of resolutions by spatial indexing, a spatial index having a plurality of nodes, where each node of the spatial index represents a cluster of data of the data set at a corresponding resolution that includes a set of the points; selecting a lowest resolution cluster of data from the spatial index; calculating a point density in a coordinate system of the display screen resulting from data at the resolution of the selected cluster of data, wherein the point density is calculated as a number of display screen pixels per point of the cluster of data; for any visible data in the selected cluster of data for a type of visualization to be shown on the display screen, comparing the point density in the display screen's coordinate system to a configured threshold; if the point density in the display screen's coordinate system is below the configured threshold, considering the visible data in the selected cluster of data is at a resolution appropriate for visualization, and returning the visible data in the selected cluster of data for display on the display screen; and if the point density in the display screen's coordinate system is above the configured threshold, selecting one or more next-higher resolution clusters of data from the spatial index, and repeating the calculating, comparing and the considering and returning, or the selecting one or more next-higher resolution clusters, as the case may be, for the one or more next-higher resolution clusters of data.