Introduction to 2D and 3D features

When you author a map, you can use both 2D and 3D feature layers in it. The construction tools that are available on feature template tool palettes are determined by the 2D or 3D data source and how a template is configured.

When you create a feature class, choose a feature type that best meets the cartographic requirements for the objects or data points you are compiling, the information you need to capture, and the type of analysis that will be performed.

The following sections describe the feature types that can be used when compiling and editing feature data.

Point, line, and polygon features

Point, line, and polygon features store ordered pairs of x- and y-coordinates with their geometry. To make them 3D z-aware, configure them to store z-values when you create a feature class.

• Point features store one set of coordinates per feature.
• Polyline and polygon features store one set of coordinates for each vertex.

You can use existing 2D features in scenes or add z-values to 2D features using geoprocessing tools. A few of the available methods are described in the following table:

Use 2D features in 3D scenes	Add z-values
Define layer elevation properties to derive z-values directly from a surface, relative to a surface, or at an absolute height from z-values stored with the feature geometry. Extrude features to 3D symbology.	Create z-aware features from 2D features using height values in an attribute field. Create z-aware features by interpolating z-values from a surface.

Point features

A point feature has neither length nor area at a given scale at x, y, and z locations.

• Point features are used to model features that don’t require lines or area to store information or convey meaning. Examples include site addresses, entities, and trees.
• Multipoint features store collections of point features as a single feature with one set of attributes. They are commonly used to simplify large datasets and improve performance, for example, with lidar feature data. Multipoint features require a multipoint feature class.

Polyline features

A polyline feature comprises straight and curved line segments that have length but not area at a given scale. The segments are constructed between vertices.

• Polyline features are used primarily to model linear and curvilinear features that require length but not area, for example, roads or streams.
• Multipart polyline features store collections of discontinuous linear parts with one set of attributes, for example, a road segment terminating at an earthen tunnel and reappearing on the other side.

Polygon features

A polygon feature is a fully enclosed planar region comprising straight and curved line segments. The segments are constructed between vertices.

• Polygon features are used to model planar regions that require area, for example, lakes or building footprints.
• Multipart polygon features store collections of noncontiguous polygon features with one set of attributes, for example, building footprints inside a compound.