Interface ITopology2

All Superinterfaces:
ITopology, Serializable
All Known Implementing Classes:
ITopology2Proxy, Topology

public interface ITopology2
extends ITopology, Serializable

Provides access to members that control a topology.


A Topology is a collection of simple feature classes within the same feature dataset that participate in topological relationships with a set of rules that govern those relationships. Topologies can have multiple feature classes in the same topological role. A feature dataset may have multiple topologies but a feature class can only belong to one topology and only simple feature classes may participate in a topology. Each topology has one associated topology graph. The topology graph is a planar representation of the geometries in the feature classes participating in a geodatabase topology. If you need to access the topology graph directly for working with topology primitives such as edges and nodes, see the ITopologyGraph help.

When new features are created, edited or deleted, the topology is responsible for creating or modifying a dirty area that will encompass the envelope of the feature. A dirty area is a special type of feature under which, the state of the topology is unknown. Features that are covered by dirty areas can still be edited and queried, but their topological relationships cannot be guaranteed to be correct. A dirty area must be validated in order to discover the topology of its underlying features and guarnatee their correctness.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Method Summary
 double getZClusterTolerance()
          The z cluster tolerance of the topology.
Methods inherited from interface com.esri.arcgis.geodatabase.ITopology
addClass, getCache, getClusterTolerance, getDirtyArea, getFeatureDataset, getMaximumGeneratedErrorCount, getState, getTopologyID, removeClass, validateTopology

Method Detail


double getZClusterTolerance()
                            throws IOException,
The z cluster tolerance of the topology.


The ZClusterTolerance property returns the Z cluster tolerance that was specified when the topology was built. As with the cluster tolerance, the Z cluster tolerance of the topology cannot be changed. In order to modify the Z cluster tolerance, the topology must be deleted and rebuilt with the new ZClusterTolerance value.

Unlike the cluster tolerance property, the ZClusterTolerance value indicates cluster tolerance distance as well as the Z clustering model that applies to the topology. A ZClusterTolerance value of 0 signifies the Building model, Z values of coincident vertices are not changed. A ZClusterTolerance value greater than 0 signifies the Terrain model, Z values of coincident vertices that are within the Z clsuter tolerance will be averaged together, based on the ZRank assigned to the features. (see ITopologyClass::ZRank )

ZClusterTolerance will return a value of -1 for any topology:

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Supported Platforms

Windows, Solaris, Linux

The tolerance
IOException - If there are interop problems.
AutomationException - If the ArcObject component throws an exception.