Gorgeous Gorge Illuminated Terrain

Why we love it

The Green River cuts through 91 miles of red sandstone cliffs to form a region in the Western US known as Flaming Gorge. We love how this terrain map captures the landscape’s stark beauty. Custom hillshade adds depth and drama while modest terrain coloring plays a strong contrast to river symbology. This map could act as a background, or stand on its own to showcase the morphology.

Why it works

Carefully rendered terrain takes center stage. This map works because it creates a realistic landscape with multiple point sources for illumination and shadows based on local lighting. The map authors employ their own Sky Model techniques to generate custom hillshades. This advanced method is available to ArcGIS users, too.

Important steps

Download tools

Download and install Terrain Tools for ArcGIS, which includes different techniques for terrain representation including the Sky Models used here, as well as sample data and a workbook.

Download Terrain Tools
Choose how you will hillshade

Use a default list of hillshading directions and weights based on CIE Sky Models, or create your own with the PC-based SkyLuminance tool (provided with Terrain Tools) to generate your own list.

Techniques for representing terrain
Select Sky Luminance

Run the Sky Luminance tool, which is included in the Terrain Tools download. In the tool, select a sky luminance type or build a custom one with hillshading directions and weights you want to use. Then use the resulting txt file as an input in the Sky Model tool itself.
Be patient

The tool will need to do hundreds of hillshadings (based on the length of your list), so it may take a bit of time.

Data and software

The only data required is a DEM. The DEM in this map was downloaded from the US Geological Survey's The National Map Viewer. Software used: ArcGIS Desktop, Terrain Tools for ArcGIS

USGS Map Viewer
Analysis

The authors’ Sky Model hillshade method is implemented in Esri’s Terrain Tools which users can download and use in ArcMap and ArcGIS Pro.
Time

The hillshade methodology was developed through many years of collaborative research. The making of this particular map took only a few hours.

Overcast looks best

The overcast sky model used here tends to work well in canyons and valleys.
Exploit the shadows

This type of hillshading exploits shadows. Add vertical exaggeration to your DEM to enhance the shadowing effect.
Use the models to determine what sky to use

Use directional sky models, such as clear day, for more mountainous areas.

General sky models for illuminating