SOAP_Geometry_Overview

O V E R V I E W

Geometry Service

A geometry service contains utility methods which provide access to sophisticated and frequently used geometric operations. An ArcGIS Server Web site can only expose one Geometry service with the static name "Geometry". Note that geometry input and output, where required, is always packaged as an array.

Use a geometry service to:

Buffer, densify, project, relate, and simplify geometry
Calculate areas, lengths, and label points for geometry
Edit and construct geometries (splitting polygons, constructing offset polylines, etc)
Return well known ids and text strings for spatial references and units

WSDL syntax

http://<Web Server Hostname>/<ArcGIS Instance>/services/Geometry/GeometryServer?wsdl

Working with a geometry service

Geometry service methods typically take as input a spatial reference (SR) and an array of geometries assumed to be in that spatial SR. This SR cannot be null. This allows callers to avoid duplicating the spatial reference within each geometry in the array. The geometry returned from a method call is not associated with a SR. It is the consumers responsibility to associate the returned geometries with the correct SR.

Finding a Well-Known ID

Working with a geometry service often involves defining a spatial reference, transformation and/or unit. The International Association of Oil & Gas Producers (OGP) maintains a set of internationally recognized numeric codes to identify standard spatial references (coordinate systems), datum transformations and linear and angular units of measure. The codes are termed EPSG codes or "factory codes" from the European Petroleum and Survey Group which was absorbed into the OGP. ESRI has also defined a set of unique numeric codes to identify the same or similar geometric entities. Other authorities and groups can define their own unique numeric codes as well. In order to accommodate multiple authorities without overlapping codes, the geometry service uses an explicitly defined range of codes for known and unknown (custom) authorities. The codes are designed to identify an commonly recognized geometric entity, thus each code is termed a "well-known id". Here are the current rules for mapping WKID ranges to default authority names used by a geometry service:

EPSG codes map to the WKID code range 1000 - 32768. EPSG version: 7.4.1
ESRI codes map to the WKID code range 33000 - 199999. Current ESRI PE (projection engine) library version: 10.0
Custom codes map to the WKID code range 200000 - 209199.

WKIDs for the EPSG and ESRI authorities are available for the following entities:

Spatial Reference - Geographic Coordinate Systems
Type

Type2

Type3

Spatial Reference - Planar (Projected) Coordinate Systems
Type

Type2

Type3

Type4

Datum Transformations

Type
Type2

Type3

Units
Type

Type2

Methods

Proxy method	Description
AutoComplete	Constructs polygons that fill in the gaps between existing polygons and a set of polylines.
Buffer	Buffers an array of geometries by each distance specified in an array of distances.
ConvexHull	Constructs the convex hull of the input geometries.
Cut	Splits input polylines or polygons where they cross a cutting polyline.
Densify	Converts non-linear geometry to linear geometry. Adds vertices to linear geometry.
DensifyGeodesic	Connects input vertices with densified approximations to geodesic paths between them.
Difference	Constructs the set-theoretic difference between an array of geometries and another geometry.
FindSRByWKID	Defines a spatial reference based upon its well known identifier (WKID) and optionally a WKID for a vertical datum.
FindSRByWKT	Defines a spatial reference based upon its well known text string (WKT) and optionally a WKT for a vertical datum.
FindUnitsByWKID	Finds a predefined linear or angular unit of measure based on its EPSG or ESRI WKID.
FindUnitsByWKT	Finds a predefined linear or angular unit of measure based on its EPSG definition string.
Generalize	Applies Douglas-Poiker generalization to the input polylines and polygons.
GetAreasAndLengths	Calculates area and perimeter length for each polygon.
GetAreasAndLengths2	Calculates area and perimeter length for each polygon, allowing specification of output units.
GetDistance	Reports the shortest distance between two geometries.
GetDistanceGeodesic	Reports the shortest geodesic distance between two geometries.
GetLabelPoints	Calculates points for label placement inside each input polygon.
GetLengths	Calculates length for each input polyline.
GetLengths2	Calculates length for each input polyline, allows specification of output units.
GetLengthsGeodesic	Calculates the geodesic length for each input polyline, allowing for specification of output units.
Intersect	Constructs the set theoretic intersection of each input and another geometry.
Offset	Constructs offset copies of the input polylines or polygons.
Project	Projects an array of geometries from their current spatial reference to a destination spatial reference.
Relation	Determines the pairs of geometries from the input geometry arrays that participate in the specified spatial relation.
Reshape	Reshapes a polyline or polygon using a reshaping line.
Simplify	Generates topologically correct geometry.
TrimExtend	Trims or extends each input polyline to meet another polyline.
Union	Constructs the set-theoretic union of the inputs.