ABSTRACT
This chapter focuses on the middle range of capabilities, 3D display, and describes some of the techniques that are available to geologists to help them analyze and communicate their information. The most common uses of this technique combine surface and subsurface geologic information with a digital elevation model. A series of vertically registered surfaces can be used to represent a portion of the earth’s crust by presenting information on individual subsurface layers. This technique is popular because it displays data in form often available to geologists, discrete surfaces rather than continuous volumetric data. 2D display representations include surfaces, multiple layers, fence diagrams, and stereo images. These 2D processes are excellent tools for storing, manipulating and combining surfaces, but geologists require 3D capabilities for most applications. The fence diagram is a classic technique for displaying geologic information in three dimensions. Geologists have used stereo views provided by airphotos for many years because stereo provides an excellent representation of the earth’s surface.
