ArcObjects Library Reference (Geometry)

IVector3D Interface

Provides access to 3D vector properties and operations.

Product Availability

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

Description

A 3 Dimensional vector with an X Component, Y Component, and Z Component that correspond to the X-Axis, Y-Axis, and Z-Axis respectively. The 3 Dimensional vector can also be defined in terms of spherical coordinates as an angle of rotation (Azimuth) from the YZ-Plane, angle of displacement (Inclination) from the XY-Plane, and a length (Magnitude). This vector can be manipulated by any of the general Vector operations as well as operations specific to the third dimension.

Members

		Description
	AddVector	Construct a new vector by adding a different vector to this vector.
	Azimuth	The vector's azimuth angle in radians.
	ComponentByIndex	The component corresponding to a given index.
	ConstructAddVector	Set this vector by adding two input vectors.
	ConstructCrossProduct	Set this vector equal to the cross product of the two input vectors.
	ConstructDifference	Set the vector by taking the difference of point1 and point2 (so the vector would go from point2 to point1).
	ConstructSubtractVector	Set this vector by subtracting the second input vector from the first one.
	CrossProduct	Returns the cross product of this vector and another vector.
	Dimension	The dimension of this vector.
	DotProduct	Returns the dot product of this vector and another vector.
	Inclination	The vector's inclination in radians.
	IsEmpty	Indicates if the vector is empty (unset).
	Magnitude	The length of the vector.
	Move	Move the vector by adding a shift value to each component.
	Normalize	Normalize the vector (scale it to magnitude = 1).
	PolarMove	Modify the vector by adding to its polar components. Angles are in radians.
	PolarQuery	Get the vector's polar components. Angles are in radians.
	PolarSet	Set the vector using polar components. Angles are in radians.
	QueryComponents	Get the values of the vector's components.
	Rotate	Rotate the vector around an axis defined by another vector. The angle is in radians.
	Scale	Scale the vector by the given factor.
	SetComponents	Set the values of the vector's components.
	SetEmpty	Makes the vector empty (unset).
	SubtractVector	Construct a new vector by subtracting a different vector from this vector.
	XComponent	The vector's X component.
	YComponent	The vector's Y component.
	ZComponent	The vector's Z component.

Inherited Interfaces

Interfaces	Description
IVector	Provides access to vector properties and operations.

CoClasses that implement IVector3D

CoClasses and Classes	Description
Vector3D	A 3D vector containing dx, dy, and dz components.

Remarks

Vector3D Example

[C#]

private static object _missing = Type.Missing;

public static IGeometry GetMultiPatchGeometry()

{

const double ConeBaseDegrees = 360.0;

const int ConeBaseDivisions = 36;

const double VectorComponentOffset = 0.0000001;

const double ConeBaseRadius = 6;

const double ConeBaseZ = 0.0;

const double ConeApexZ = 9.5;

//Vector3D: Cone, TriangleFan With 36 Vertices

IGeometryCollection multiPatchGeometryCollection = new MultiPatchClass();

IPointCollection triangleFanPointCollection = new TriangleFanClass();

//Set Cone Apex To (0, 0, ConeApexZ)

IPoint coneApexPoint = ConstructPoint3D(0, 0, ConeApexZ);

//Add Cone Apex To Triangle Fan

triangleFanPointCollection.AddPoint(coneApexPoint, ref _missing, ref _missing);

//Define Upper Portion Of Axis Around Which Vector Should Be Rotated To Generate Cone Base Vertices

IVector3D upperAxisVector3D = ConstructVector3D(0, 0, 10);

//Define Lower Portion of Axis Around Which Vector Should Be Rotated To Generate Cone Base Vertices

IVector3D lowerAxisVector3D = ConstructVector3D(0, 0, -10);

//Add A Slight Offset To X or Y Component Of One Of Axis Vectors So Cross Product Does Not Return A Zero-Length Vector

lowerAxisVector3D.XComponent += VectorComponentOffset;

//Obtain Cross Product Of Upper And Lower Axis Vectors To Obtain Normal Vector To Axis Of Rotation To Generate Cone Base Vertices

IVector3D normalVector3D = upperAxisVector3D.CrossProduct(lowerAxisVector3D) as IVector3D;

//Set Normal Vector Magnitude Equal To Radius Of Cone Base

normalVector3D.Magnitude = ConeBaseRadius;

//Obtain Angle Of Rotation In Radians As Function Of Number Of Divisions Within 360 Degree Sweep Of Cone Base

double rotationAngleInRadians = GetRadians(ConeBaseDegrees / ConeBaseDivisions);

for (int i = 0; i < ConeBaseDivisions; i++)

{

//Rotate Normal Vector Specified Rotation Angle In Radians Around Either Upper Or Lower Axis

normalVector3D.Rotate(-1 * rotationAngleInRadians, upperAxisVector3D);

//Construct Cone Base Vertex Whose XY Coordinates Are The Sum Of Apex XY Coordinates And Normal Vector XY Components

IPoint vertexPoint = ConstructPoint3D(coneApexPoint.X + normalVector3D.XComponent,

coneApexPoint.Y + normalVector3D.YComponent,

ConeBaseZ);

//Add Vertex To TriangleFan

triangleFanPointCollection.AddPoint(vertexPoint, ref _missing, ref _missing);

}

//Re-Add The Second Point Of The Triangle Fan (First Vertex Added) To Close The Fan

triangleFanPointCollection.AddPoint(triangleFanPointCollection.get_Point(1), ref _missing, ref _missing);

//Add TriangleFan To MultiPatch

multiPatchGeometryCollection.AddGeometry(triangleFanPointCollection as IGeometry, ref _missing, ref _missing);

return multiPatchGeometryCollection as IGeometry;

}

private static IPoint ConstructPoint3D(double x, double y, double z)

{

IPoint point = ConstructPoint2D(x, y);

point.Z = z;

return point;

}

private static IPoint ConstructPoint2D(double x, double y)

{

IPoint point = new PointClass();

point.PutCoords(x, y);

return point;

}

private static double GetRadians(double decimalDegrees)

{

return decimalDegrees * (Math.PI / 180);

}