The Colorado Plateau and the Grand Canyon occupy the foreground of this north oriented view of the western United States. Great Salt Lake and the Bonneville Salt Flats can be seen in the northwest. To the west lies the north-south trending basin and range physiographic province. The snow-capped Rocky Mountains rise in the east. Elevations within the scene range from 150 to 4,400 meters above sea level.

Floating landscapes

The Colorado Plateau scene is shown as a landscape floating in isolation from contiguous geographic areas. Floating landscapes are common and offer advantages for 3D landscape presentation: 1) data requirements are finite, 2) the sides of a scene converge toward the background, reinforcing perspective, 3) the crenelated edges show elevation differences providing visual cues about three dimensionality, and, 4) landscapes can be viewed from high or low camera elevations with equal effectiveness.

DEM enhancement

The scene was created from a square DEM, 10 degrees per side, with one kilometer resolution. When initially rendered, canyons appeared with rounded edges because of the DEMís low resolution. Photoshop was used to enhance the canyons on the DEM prior to rendering the final scene in Bryce. A light application of the unsharp mask filter helped define the rugged canyon rims. Mountain peaks were not sharpened because of their tendency to spike unnaturally upwards.

Snowline

Colors on the Colorado Plateau surface derive from a satellite image, with one kilometer resolution, which was draped (mapped) on the DEM. The satellite image shows water and vegetation zones. The copyrighted satellite image, windowed from a world database, is a product of Arc Science Simulations, Inc.

Problem

The color of elevation-influenced vegetation zones in the western United Statesóbeige desert lowlands and green montane forestsócontradicts the cartographic convention for showing hypsometric tints, which usually are dark green lowlands and pale highlands. When highlands are cloaked in dark green (a visually recessive color), as is the case with the Colorado Plateau, 3D properties become subdued.

Solution

An artificial snow line (white) graphically elevates the loftiest mountain ranges above the green forests. The snow was added to the satellite image with Photoshop before rendering the final scene in Bryce. It was created by masking the satellite image with an inverted copy of the grayscale DEM, which removed color from the mountain tops, simulating snow. The snow mask can be made to appear gradual or abrupt, opaque or translucent, by subtly adjusting Photoshopís curves.

Dark forests obscure mountains on the original satellite image (left). Color adjustments and a snow mask help to define mountains (right).

Procedural texture

Draped images on DEM surfaces often look unnaturally smooth, especially when stretched by vertically exaggerated relief. Adding a procedural texture can give the scene a more organic look. The illusion of desert rubble was added to the Colorado Plateau with a subtle sandstone texture selectively applied to flat lowland areas.

Return