1. A method of representing a buffer about a feature represented on an ellipsoid or round-object model, the method comprising: accessing a definition of a buffer stored on one or more computer readable medium in a format readable by a computer application, the definition of the buffer comprising a plurality of arcs around a feature on an ellipsoid or round-object model wherein each of the arcs are defined using three points at least one of which is defined using geodetic coordinates, wherein the three points comprise two endpoints of a given arc defined using geodetic coordinates and a data point defining the curvature of the arc; rendering the buffer by rendering the plurality of arcs; and displaying the rendered buffer to a user at a computing system display.