Abstract

Hillshading with Sky Models in ArcGIS
Track: Cartography and Map Production
Authors: Patrick Kennelly, James Stewart

ArcMap's Spatial Analyst extension includes a Hillshade tool that uses a theoretical point source illumination vector whose azimuth and altitude can be adjusted by the mapmaker. Although hillshading with point source illumination is an effective way to shade terrain maps for a three-dimensional (3D) effect, more stylized shadings are possible by choosing from a gamut of sky models used in other industries such as computer graphics and architecture. We present a desktop application and Python script that can be run within ArcMap and used to precisely shade terrain using a number of sky models adopted by the International Commission on Illumination (CIE).