# GeometryBuilder

Geometry builders allow you to create and modify geometries incrementally. This is the base class for a range of geometry builders, such as a PointBuilder, PolylineBuilder and PolygonBuilder. Each GeometryType has a corresponding type of builder. You can create and modify polygons with PolygonBuilder, envelopes with EnvelopeBuilder, and so on. Use a geometry builder in editing workflows where you need to build up or edit geometry one vertex at a time, for example, when you need to add or edit a vertex from a custom streaming GIS data source. You can either create an empty geometry builder and build up the shape of a Geometry, or you can create a geometry builder with an existing Geometry and modify it.

When you construct the builder, you can explicitly set its SpatialReference or you can construct the builder with a geometry and the builder will adopt the Geometry.spatialReference. Once set, the SpatialReference cannot be changed. The SpatialReference of any geometry or coordinates added to the builder must be compatible with the SpatialReference of the builder, as they will not be reprojected. The SpatialReference of a geometry added to the builder can be null, in which case the object is assumed to have the same SpatialReference as the builder it is added to.

There are other ways to create and edit geometries. If you know all the geometry coordinates up front, then you can use geometry constructors, such as Polygon, to create the geometry. If you are going to create a new geometry as a result of a topological operation, such as the buffer operation, then explore the GeometryEngine. If you want your app users to interactively create or edit geometries in the user interface then use the GeometryEditor.

#### Since

200.1.0

#### See also

#### Inheritors

## Properties

True if the geometry builder currently contains any curve segments, false otherwise. ArcGIS software supports polygon and polyline geometries that contain curve segments (where Segment.isCurve is true, sometimes known as true curves or nonlinear segments). Curves may be present in certain types of data, such as Mobile Map Packages (MMPKs), or geometry JSON.

True if the geometry builder supports geometries with m values, false otherwise. M values are often referred to as measures, and are used in linear referencing workflows on linear datasets. NaN is a valid m value. If true, m values are stored for each vertex of the constructed Geometry. Geometries with m values are created by using setters or constructors that take an m value as a parameter.

True if the geometry builder supports geometries with z values, false otherwise. Z values are generally used as a z coordinate, indicating height or elevation. NaN is a valid z value. If true, z values are stored for each vertex of the constructed Geometry. Geometries with z values are created by using setters or constructors that take a z value as a parameter.

True if no coordinates have been added to this geometry builder, false otherwise. An empty geometry builder may have a valid SpatialReference, even without coordinates.

True if the geometry builder contains sufficient points to show a valid graphical sketch, false otherwise. This can be used as an initial lightweight check to see if the current state of a builder produces a non-empty geometry. For example, it may be used to enable or disable functionality in an editing user interface. The exact requirements vary depending on the type of geometry produced by the builder:

The spatial reference for the geometry. Once set, the SpatialReference of the geometry builder cannot be changed. Ensure that all objects added to the builder have a compatible SpatialReference.

## Functions

Replaces the geometry currently stored in the geometry builder with the new geometry. This method can be used as an alternative to creating a new builder from an existing geometry. Note that this does not update the spatial reference of the builder and the builder geometry is cleared if the geometry is null. Geometries with curves are supported.

Returns the geometry this geometry builder is constructing or modifying.