The Feature to Point Processor can be used to dynamically produce a point from an event record’s polygon or polyline geometry. The processor returns the point as the centroid of the original geometry.
Examples
The following are example uses of the Feature to Point Processor:
- Calculating the centroid of a polygon feature can be used to show the center of mass in real time. For example, a polygon feature representing a live hurricane can be reduced to a point centroid to show the generalized eye of the storm.
- Reducing polygon or polyline features to a point can be used to improve event record throughput and storage performance. Polygon or polyline features with thousands of vertices can impact the performance of your real-time analyses in GeoEvent Server.
Usage notes
Keep the following in mind when working with the Feature to Point Processor:
- The processor requires the field containing the event record’s geometry be specified. A geometry field name can be specified, or the GEOMETRY tag can be applied to a field in a GeoEvent Definition to identify the geometry field.
- The Geometry Field parameter will show the name of every field from every GeoEvent Definition containing a data type of geometry. When selecting the geometry field by name, choose the name of the correct geometry field that corresponds to the event record’s GeoEvent Definition.
- The processor can be configured to replace the event record’s geometry with the point centroid, or it can place the point centroid into a new geometry field using the Replace Geometry parameter. Altering an event record's schema by adding a new field requires GeoEvent Server to create a new GeoEvent Definition. The new GeoEvent Definition will be managed by GeoEvent Server and deleted if changes are made to the processor or the GeoEvent Service in which the processor is used.
- Choosing Yes for the Tag the New Geometry Field as Geometry parameter explicitly tells GeoEvent Server which geometry field should be treated as the event record’s realized geometry for subsequent processing or output.
- When sending event records from the processor to a feature service output, ensure only one geometry field exists in the outbound GeoEvent Definition.
Parameters
The following are the parameters for the Feature to Point Processor:
| Parameter | Description |
|---|---|
|
Name |
A descriptive name for the processor used for reference in GeoEvent Manager. |
|
Processor |
Specifies the processor selected. |
| Geometry Type | Specifies the current geometry type of the event records to be processed. The default is Polygon.
|
| Replace Geometry | Specifies whether to replace the current event record geometry with the geometry of the point centroid. The default is Yes.
|
| Geometry Field | The name of the geometry field or the GEOMETRY tagged field from the inbound event record the processor will use to calculate the point centroid. The actual geometry of the specified geometry field must match the geometry type specified in the Geometry Type parameter. |
| New Geometry Field (Conditional) | The name of the new geometry field where the point centroid geometry will be stored. The parameter is shown when Replace Geometry is set to No and is hidden when set to Yes. |
| New GeoEvent Definition Name (Conditional) | The name assigned to the new GeoEvent Definition. The new GeoEvent Definition will combine the schema of the inbound event record with the additional new geometry field. The parameter is shown when Replace Geometry is set to No and is hidden when set to Yes. |
| Tag the New Geometry Field as Geometry (Conditional) | Determines whether the new geometry field created by the processor will be tagged as GEOMETRY. The GEOMETRY tag is used by GeoEvent Server to identify the event record’s realized geometry when multiple geometry fields are present. The default is No. This parameter is shown when Replace Geometry is set to No and is hidden when set to Yes. |
Considerations and limitations
There are several considerations to keep in mind when using the Feature to Point Processor:
- The Feature to Point Processor only supports polygon and polyline geometry types. Other geometry types such as multipoint or envelope are not supported.
- The processor can only process one type of geometry on inbound event data, for example, polygon or point, but not both. If both types of geometry are present in the inbound event data, consider implementing a second Feature to Point Processor to process each supported type of geometry—one to process the polygon geometries and the other to process the polyline geometries.
- Consider replacing the existing event record geometry with the geometry representing the point (centroid) prior to sending the event data to a feature service. Feature services only support one geometry type field, so whichever field is not tagged with the GEOMETRY tag will be converted and kept as a string.