z property

The z-coordinate for the point.

Geometries can have z-values, indicating values along the z-axis, which is perpendicular to both the x-axis and y-axis. Z-values indicate height above or depth below a surface, or an absolute elevation. For example, z-values are used to draw the locations of geometries in an ArcGISSceneViewController. Note that geometries are not considered true 3D shapes and are draped onto surfaces in the view, or in some cases, drawn in a single plane by using z-values. Z-values are stored on ArcGISPoint and Envelope. Since Multipoint, Polyline, and Polygon are created from a collection of ArcGISPoint, all types of geometry can have z-values.

Whether or not a geometry has z-values is determined when the geometry is created; if you use a method that has a z-value parameter, the new geometry has z-values (Geometry.hasZ is true). If you create geometries using constructors that take z-value parameters, or if you pass into the constructor points or segments that have z-values, the new geometry has z-values. A Geometry with z-values is sometimes known as a z-aware geometry.

It may be that not all vertices in your geometry have a z-value defined. NAN is a valid z-value used to indicate an unknown z-value. However, the default z-value is 0. When you get z-values from a geometry that does not have z-values, the default is 0. Check the Geometry.hasZ to determine whether a z-value of 0 means that there are no z-values in the geometry or that the z-value in the geometry's coordinates really is 0.