Interface implemented by an object that represents a clutter geometry plugin.

Compute	Clutter geometry plugin compute.
Free	Free clutter geometry plugin.
Initialize	Initializes the plugin with the plugin site.
PostCompute	Clutter geometry plugin post-compute.
PreCompute	Clutter geometry plugin pre-compute.
Register	Registers the plugin with the application.

This interface is implemented by the clutter geometry plugin.  The clutter geometry plugin is responsible for creating a collection of IAgStkRadarClutterPatch objects.  It does this by calling the Add method on the IAgStkRadarClutterPatchCollection interface returned by the ClutterPatches property of the IAgStkRadarClutterGeometryComputeParams interface passed as an input parameter to the Compute method.  The Add method constructs a new IAgStkRadarClutterPatch object, adds it to the collection, and then returns it to the caller.  The plugin should then set the new patches location and area.