The Third Spatial Dimension - Introducing Geographic Information Systems with ArcGIS - page 544

FIGURE 9-1
9. In the T/C, turn off all the images except the Digital Elevation Model (DEM) and Boat_SP83.
Open the attribute table of the DEM. Note the Value field. Each record in that field indicates the
elevation of the posts—the number of which is indicated by the Count field. Close the attribute
table.
The DEM, while it contains elevation information as an attribute was represented as flatly as everything
else (except the TIN). We can alter that. First, let's display it with more color and more differentiation
between the heights.
10. Bring up the Properties window of cole_dem. Choose Symbology. Set the window to Show:
Classified. Make 25 classes. Right-click the bar of the Color Ramp. Uncheck Graphic View. From
the drop-down menu, choose Elevation #2. Click Apply, then OK. Take a quick look at
the Value symbols in the Table of Contents. Move cole_dem around with the navigation tool to
look at it.
Things are still flat—but more colorful and obvious. Now we add the vertical dimension. We actually have
two sources of elevation information: the TIN, of course, and the elevation attribute (VALUE) contained in
the DEM's table.
11. Bring up the Properties window of cole_dem again. Note that there is a Base Heights tab.
Select it. In the “Elevation from surfaces” area choose the radio button “Floating on a custom
surface”. Choose the DEM itself as the surface to use. Slide the Layer Properties window away
from the display, so you can see the effect as you press Apply. Close the Layer Properties
window. Then concentrate on the river bend area, using pan, zoom, and navigation. One image
you can see is shown in Figure 9-2.