ISpatialReference3 Interface

Provides access to additional members that associate a spatial reference with a vertical coordinate system.

When To Use

Use ISpatialReference3 to work with the vertical coordinate system part of a spatial reference.

Members

	Name	Description
	Abbreviation	The abbreviated name of this spatial reference component.
	Alias	The alias of this spatial reference component.
	ApplyPrecision	Applies the measure and z value precisions.
	ApplyXYPrecision	Applies the XY precision.
	Changed	Notify this object that some of its parts have changed (parameter values, z unit, etc.).
	FactoryCode	The factory code (WKID) of the spatial reference.
	GetDomain	The XY domain extent.
	GetFalseOriginAndUnits	Get the false origin and units.
	GetMDomain	The measure domain extent.
	GetMFalseOriginAndUnits	Get the measure false origin and units.
	GetZDomain	The Z domain extent.
	GetZFalseOriginAndUnits	Get the Z false origin and units.
	HasMPrecision	Returns true when m-value precision information has been defined.
	HasXYPrecision	Returns true when (x,y) precision information has been defined.
	HasZPrecision	Returns true when z-value precision information has been defined.
	IsMPrecisionEqual	Returns true if the measure precisions of the two spatial references are the same.
	IsPrecisionEqual	Returns TRUE when the precision information for the two spatial references is the same.
	IsXYPrecisionEqual	Returns true if the XY precisions of the two spatial references are the same.
	IsZPrecisionEqual	Returns true if the Z precisions of the two spatial references are the same.
	Name	The name of this spatial reference component.
	PrecisionExImpl	An opaque reference to the precision information (including z/m awareness) implementation for this spatial reference.
	PrecisionImpl	An opaque reference to the precision information implementation for this spatial reference.
	ProjectionHint	Projection hint for speeding up projections.
	Remarks	The comment string of this spatial reference component.
	SetDomain	The XY domain extent.
	SetFalseOriginAndUnits	Set the false origin and units.
	SetMDomain	The measure domain extent.
	SetMFalseOriginAndUnits	Set the measure false origin and units.
	SetZDomain	The Z domain extent.
	SetZFalseOriginAndUnits	Set the Z false origin and units.
	SpatialReferenceImpl	SpatialReferenceImpl.
	VerticalCoordinateSystem	The VCS associated with this spatial reference.
	ZCoordinateUnit	The unit for the Z coordinate.

ISpatialReference3.ProjectionHint Method

Projection hint for speeding up projections.

Public Sub ProjectionHint ( _
    ByVal Geometry As IGeometry, _
    ByVal targetSR As ISpatialReference, _
    ByRef Direction As esriTransformDirection, _
    ByRef pXForm As ITransformation, _
    ByRef ProjectionHint As Integer _
)

public void ProjectionHint (
    IGeometry Geometry,
    ISpatialReference targetSR,
    ref esriTransformDirection Direction,
    ref ITransformation pXForm,
    ref int ProjectionHint
);

Description

Each geographic or projected coordinate system has a horizon. The horizon defines the mathematical limits of the coordinate system. As an example, transverse Mercator is limited to longitude values that are within +/-45 degrees of the central meridian. Most projection workflows are local. That is, all geometries of a feature class are within the horizons of the input and output coordinate systems. The process of checking whether a geometry is within, crosses, or is outside a horizon takes time. You can use the projectionhint method to calculate whether the envelope or bounding geometry of a feature class is within the applicable horizons. If it is, you can add a flag to the ProjectEx5 method to omit horizon checking.

You can also have the projectionhint method check for a geographic (datum) transformation. In the SpatialReferenceEnvironment, the GeoTransformationOperationSet stores active transformations. Normally, none are loaded by default, but if you've loaded several transformations previously, you can use projection hint to return the appropriate one and in which direction to apply it for this projection operation.

The projectionhint values are:

  esriProjectionHintNoHorizonCheck        =  0,
  esriProjectionHintCheckPCSHorizon       =  1,
  esriProjectionHintCheckGCSHorizon       =  2,
  esriProjectionHintFindGeoTransformation =  4,
  esriProjectionHintDefault               =  7,
  esriProjectionHintExplore               =  8,
  esriProjectionHintDoNotProject          = 16  // useful for isEqualNoName

ISpatialReference3.VerticalCoordinateSystem Property

The VCS associated with this spatial reference.

Public Property VerticalCoordinateSystem As IVerticalCoordinateSystem

public IVerticalCoordinateSystem VerticalCoordinateSystem {get; set;}

Description

ISpatialReferenceFactory3 srf3 = new SpatialReferenceEnvironmentClass();

            IVerticalCoordinateSystem vcs1, vcs2;

            vcs1 = srf3.CreateVerticalCoordinateSystem(5702);//NGVD_1929

            vcs2 = srf3.CreateVerticalCoordinateSystem(5703);//NAVD_1988

            ISpatialReference sr1, sr2;

            sr1 = srf3.CreateSpatialReference(4269);//GCS_North_American_1983

            ((ISpatialReference3)sr1).VerticalCoordinateSystem = vcs1;

            sr2 = srf3.CreateSpatialReference(5070);//NAD_1983_Contiguous_USA_Albers

            ((ISpatialReference3)sr2).VerticalCoordinateSystem = vcs2;

            IProjectedCoordinateSystem pcs2 = (IProjectedCoordinateSystem)sr2;

            IGeographicCoordinateSystem gcs1 = (IGeographicCoordinateSystem)sr1;

            IGeographicCoordinateSystem gcs2 = pcs2.GeographicCoordinateSystem;

            IHVCompositeDatumTransformationEditor edit = new HVCompositeDatumTransformationEditorClass();

            IHVDatumTransformation hvdt;

            edit.SetSpatialReferences(gcs1, gcs2);

            hvdt = edit.CreateHVDatumTransformation(110011);//PE_VT_NGVD29_TO_NAVD88_NAD83_ECW

            edit.Add(hvdt, esriTransformDirection.esriTransformForward);

            IHVCompositeDatumTransformation hvcdt = edit.CreateNew();

            ITransformation transform = (ITransformation)hvcdt;

            IPoint pnt = new PointClass();

            pnt.SpatialReference = sr1;

            pnt.PutCoords(4, 3);

            ((IZAware)pnt).ZAware = true;

            pnt.Z = 5;

            ((IGeometry5)pnt).ProjectEx5(sr2, esriTransformDirection.esriTransformForward, transform, false, 0, 0, ((int)esriProjectionHint.esriProjectionHintDefault) & ((int)esriProjectionHint.esriProjectionHintFindGeoTransformation));

            double x, y, z;

            pnt.QueryCoords(out x, out y);//10421841.071915826, 3982079.5947264349

            z = pnt.Z;//1.5240030480060962

Inherited Interfaces

Interfaces	Description
ISpatialReference2	Provides access to additional members that control a SpatialReference.
ISpatialReference	Provides access to members that control a SpatialReference.
ISpatialReferenceInfo	Provides access to members that control the properties common to all components of a spatial reference system.

Classes that implement ISpatialReference3

Classes	Description
GeographicCoordinateSystem	Creates a geographic coordinate system.
ProjectedCoordinateSystem	Creates a projected coordinate system.