About 3D features

You may want to visualize feature data, as well as surfaces, in a perspective view. However feature data (shape) is different from surface data and what it can be used to represent. Some GIS features store z-values, or height position, with their geometry. This can be used to display the feature in the 3D view. Two-dimensional feature data (which does not have 3D properties) can also be viewed in 3D, for example, by using extrusion or by draping features over elevation surfaces.

Feature geometries

Feature data differs from surface data in representing discrete objects, rather than continuous phenomena. Features typically have a shape (geometry) and attributes.

Some typical feature geometries are point, line, and polygon:

• Point features might represent mountain peaks, telephone poles, or well locations.
• Lines might represent roads, streams, or ridgelines.
• Polygons might represent buildings, lakes, or administrative areas.

Z-values

The attributes of features can store values that refer to the elevation or height of the features. Some GIS features store elevation values within the feature geometry itself; for example, PointZ features are stored as a set of x,y,z coordinates. You can use z-values in the geometry, or attributes of features, to display the features in a 3D view.

Sometimes features lack elevation or height values. You can still view these features in a 3D view by draping or extruding them (see the following section).

Draping and extruding features

If you have a surface model for the area, you can use the values in the model as z-values for the features. This is called draping the features. You can also use this technique to visualize image data in 3D.

If you want to show building features in 3D, you can extrude them using an attribute, such as building height or number of stories. You can also extrude features based on an arbitrary value.

Sometimes you'll want to view 2D features in a 3D view with z-values taken from some attribute other than a height value. For example, you might create a view that shows city points extruded into columns based on their population.

Displaying features in 3D, whether they are features already with 3D geometries or 2D features that do not have a z-value defined, can be customized through ArcGlobe and ArcScene layer properties.

See Displaying features in ArcGlobe and Displaying features in ArcScene for more information.