fr.cnes.sirius.patrius.fieldsofview

Class RectangleField

java.lang.Object

fr.cnes.sirius.patrius.fieldsofview.RectangleField

All Implemented Interfaces:

IFieldOfView, IGeometricFieldOfView, Serializable

public class RectangleField
extends Object
implements IGeometricFieldOfView

This class describes a field of view defined by a rectangle cone, to be used in "instruments" part properties. It implements the IGeometricFieldOfView interface and so provides the associated services.

Since:

1.2

Version:

$Id$

Author:

Thomas Trapier

See Also:

IFieldOfView, FieldAngularFace, Serialized Form

Concurrency :

immutable

Constructor Summary

Constructors

Constructor and Description
RectangleField(String name, Vector3D mainDirection, Vector3D approximativeU, double angularApertureU, double angularApertureV) Constructor for a field of view defined by a rectangle cone.

Method Summary

Modifier and Type	Method and Description
double	getAngularDistance(Vector3D direction, AngularDistanceType method) Computes the angular distance between a vector and the border of the field.
double	getAngularOpening(Vector3D directionIn) Get the angular opening of the Field Of View (FOV) over a given direction.
Vector3D	getMainDirection() Get the main direction of the geometrical FOV.
String	getName()
Vector3D[]	getSideAxis() Get the 4 side axis of the field of view.
Vector3D	getU() Get the U axis
Vector3D	getV() Get the V axis
Vector3D	getW() Get the W axis.
boolean	intersectUSide(double theta) This method returns true if the direction associated to the input angle theta intersect the U-side, false otherwhise.
boolean	isInTheField(Vector3D direction)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface fr.cnes.sirius.patrius.fieldsofview.IGeometricFieldOfView

getAngularDistance

Constructor Detail

RectangleField

public RectangleField(String name,
                      Vector3D mainDirection,
                      Vector3D approximativeU,
                      double angularApertureU,
                      double angularApertureV)

Constructor for a field of view defined by a rectangle cone.

Parameters:

name - the name of the field

mainDirection - the main direction of the rectangle cone

approximativeU - defines the U vector of the local frame of the rectangle cone (will be corrected to be orthogonal to the main direction vector). Can't be parallel to the main direction vector.

angularApertureU - the angular half-opening in U direction : must be strictly between 0 and PI/2

angularApertureV - the angular half-opening in V direction : must be strictly between 0 and PI/2

Method Detail

getU

public Vector3D getU()

Get the U axis

Returns:

U axis

getV

public Vector3D getV()

Get the V axis

Returns:

V axis

getW

public Vector3D getW()

Get the W axis. This represents the direction of the cone

Returns:

W axis

getSideAxis

public Vector3D[] getSideAxis()

Get the 4 side axis of the field of view.

Returns:

the 4 side axis of the field of view

getAngularDistance

public double getAngularDistance(Vector3D direction,
                                 AngularDistanceType method)

Computes the angular distance between a vector and the border of the field. The result is positive if the direction is in the field, negative otherwise.

Several methods can be defined for the computation. The user can choose the more appropriate one from the enum AngularDistanceType.

Specified by:

getAngularDistance in interface IGeometricFieldOfView

Parameters:

direction - the direction vector (expressed in the topocentric coordinate system of the object)

method - Defines the method to compute the distance from the enum AngularDistanceType

Returns:

the angular distance

isInTheField

public boolean isInTheField(Vector3D direction)

Specified by:

isInTheField in interface IFieldOfView

Parameters:

direction - a direction vector (expressed in the topocentric coordinate system of the object)

Returns:

true if the direction is in the field

getName

public String getName()

Specified by:

getName in interface IFieldOfView

Returns:

the name of the field

getAngularOpening

public double getAngularOpening(Vector3D directionIn)

Get the angular opening of the Field Of View (FOV) over a given direction. Considering the half-plane containing both the main direction of the FOV and the input direction, the angular opening is defined as the angle between the main direction and the intersection of the FOV border with the half-plane.

Specified by:

getAngularOpening in interface IGeometricFieldOfView

Parameters:

directionIn - the direction vector (expressed in the topocentric coordinate system of the object)

Returns:

the angular opening along the input direction

intersectUSide

public boolean intersectUSide(double theta)

This method returns true if the direction associated to the input angle theta intersect the U-side, false otherwhise. Theta is computed according to the following conventions:

• Theta belongs to [-π, π] and is defined in the plane given by the main axis U-V
• Theta = 0 if the associated direction is aligned with U
• Theta = &pi/2 if the associated direction is aligned with V

"U-sides" are defined as the two rectangle sides intersecting the U-axis. The two U-sides are therefore parallel to V-axis.

Knowing the angular opening of the rectangle's diagonal (called α), 3 intervals are defined, and each one holds directions that intersect a U-side:

• [-π, α-π]
• [-α, +α]
• [π-α, +π]

Parameters:

theta - angle within ]-π, π] (with respect to U-axis) associated to the direction to check.

Returns:

true if the direction defined by theta intersects the FOV on a U-side (small side defining pointed by U-axis)

getMainDirection

public Vector3D getMainDirection()

Get the main direction of the geometrical FOV. For every orthogonal section of the FOV, the main direction contains the center of such section.

Specified by:

getMainDirection in interface IGeometricFieldOfView

Returns:

The main direction of the FOV