javax.media.j3d
Class SpotLight

java.lang.Object
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  +--javax.media.j3d.SceneGraphObject
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        +--javax.media.j3d.Node
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              +--javax.media.j3d.Leaf
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                    +--javax.media.j3d.Light
                          |
                          +--javax.media.j3d.PointLight
                                |
                                +--javax.media.j3d.SpotLight

public class SpotLight

extends PointLight

The SpotLight object specifies an attenuated light source at a fixed point in space that radiates light in a specified direction from the light source. A SpotLight has the same attributes as a PointLight node, with the addition of the following:

• Direction - The axis of the cone of light. The default direction is (0.0, 0.0, -1.0). The spot light direction is significant only when the spread angle is not PI radians (which it is by default).
• Spread angle - The angle in radians between the direction axis and a ray along the edge of the cone. Note that the angle of the cone at the apex is then twice this value. The range of values is [0.0,PI/2] radians, with a special value of PI radians. Values lower than 0 are clamped to 0 and values over PI/2 are clamped to PI. The default spread angle is PI radians.
• Concentration - Specifies how quickly the light intensity attenuates as a function of the angle of radiation as measured from the direction of radiation. The light's intensity is highest at the center of the cone and is attenuated toward the edges of the cone by the cosine of the angle between the direction of the light and the direction from the light to the object being lit, raised to the power of the spot concentration exponent. The higher the concentration value, the more focused the light source. The range of values is [0.0,128.0]. The default concentration is 0.0, which provides uniform light distribution.

A spot light contributes to diffuse and specular reflections, which depend on the orientation and position of an object's surface. A spot light does not contribute to ambient reflections.

Field Summary

static int	ALLOW_CONCENTRATION_READ Specifies that the Node allows reading its spot lights concentration information.
static int	ALLOW_CONCENTRATION_WRITE Specifies that the Node allows writing to its spot lights concentration information.
static int	ALLOW_DIRECTION_READ Specifies that the Node allows reading its spot lights direction information.
static int	ALLOW_DIRECTION_WRITE Specifies that the Node allows writing to its spot lights direction information.
static int	ALLOW_SPREAD_ANGLE_READ Specifies that the Node allows reading its spot lights spread angle information.
static int	ALLOW_SPREAD_ANGLE_WRITE Specifies that the Node allows writing to its spot lights spread angle information.

Fields inherited from class javax.media.j3d.PointLight

ALLOW_ATTENUATION_READ, ALLOW_ATTENUATION_WRITE, ALLOW_POSITION_READ, ALLOW_POSITION_WRITE

Fields inherited from class javax.media.j3d.Light

ALLOW_COLOR_READ, ALLOW_COLOR_WRITE, ALLOW_INFLUENCING_BOUNDS_READ, ALLOW_INFLUENCING_BOUNDS_WRITE, ALLOW_SCOPE_READ, ALLOW_SCOPE_WRITE, ALLOW_STATE_READ, ALLOW_STATE_WRITE

Fields inherited from class javax.media.j3d.Node

ALLOW_AUTO_COMPUTE_BOUNDS_READ, ALLOW_AUTO_COMPUTE_BOUNDS_WRITE, ALLOW_BOUNDS_READ, ALLOW_BOUNDS_WRITE, ALLOW_COLLIDABLE_READ, ALLOW_COLLIDABLE_WRITE, ALLOW_LOCAL_TO_VWORLD_READ, ALLOW_PICKABLE_READ, ALLOW_PICKABLE_WRITE, ENABLE_COLLISION_REPORTING, ENABLE_PICK_REPORTING

Constructor Summary

SpotLight()
Constructs a SpotLight node with default parameters.

SpotLight(boolean lightOn, Color3f color, Point3f position, Point3f attenuation, Vector3f direction, float spreadAngle, float concentration)
Constructs and initializes a SpotLight node using the specified parameters.

SpotLight(Color3f color, Point3f position, Point3f attenuation, Vector3f direction, float spreadAngle, float concentration)
Constructs and initializes a SpotLight node using the specified parameters.

Method Summary

Node	cloneNode(boolean forceDuplicate) Used to create a new instance of the node.
float	getConcentration() Gets spot light concentration.
void	getDirection(Vector3f direction) Gets this Light's current direction and places it in the parameter specified.
float	getSpreadAngle() Gets spot light spread angle.
void	setConcentration(float concentration) Sets spot light concentration.
void	setDirection(float x, float y, float z) Sets light direction.
void	setDirection(Vector3f direction) Sets this Light's current direction and places it in the parameter specified.
void	setSpreadAngle(float spreadAngle) Sets spot light spread angle.

Methods inherited from class javax.media.j3d.PointLight

getAttenuation, getPosition, setAttenuation, setAttenuation, setPosition, setPosition

Methods inherited from class javax.media.j3d.Light

addScope, getAllScopes, getColor, getEnable, getInfluencingBoundingLeaf, getInfluencingBounds, getScope, insertScope, numScopes, removeScope, setColor, setEnable, setInfluencingBoundingLeaf, setInfluencingBounds, setScope, updateNodeReferences

Methods inherited from class javax.media.j3d.Node

cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, cloneTree, duplicateNode, getBounds, getBoundsAutoCompute, getCollidable, getLocalToVworld, getLocalToVworld, getParent, getPickable, setBounds, setBoundsAutoCompute, setCollidable, setPickable

Methods inherited from class javax.media.j3d.SceneGraphObject

clearCapability, duplicateSceneGraphObject, getCapability, getUserData, isCompiled, isLive, setCapability, setUserData

Methods inherited from class java.lang.Object

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

Field Detail

ALLOW_SPREAD_ANGLE_WRITE

public static final int ALLOW_SPREAD_ANGLE_WRITE

Specifies that the Node allows writing to its spot lights spread angle information.

ALLOW_SPREAD_ANGLE_READ

public static final int ALLOW_SPREAD_ANGLE_READ

Specifies that the Node allows reading its spot lights spread angle information.

ALLOW_CONCENTRATION_WRITE

public static final int ALLOW_CONCENTRATION_WRITE

Specifies that the Node allows writing to its spot lights concentration information.

ALLOW_CONCENTRATION_READ

public static final int ALLOW_CONCENTRATION_READ

Specifies that the Node allows reading its spot lights concentration information.

ALLOW_DIRECTION_WRITE

public static final int ALLOW_DIRECTION_WRITE

Specifies that the Node allows writing to its spot lights direction information.

ALLOW_DIRECTION_READ

public static final int ALLOW_DIRECTION_READ

Specifies that the Node allows reading its spot lights direction information.

Constructor Detail

SpotLight

public SpotLight()

Constructs a SpotLight node with default parameters. The default values are as follows:

direction : (0,0,-1)
spread angle : PI radians
concentration : 0.0

SpotLight

public SpotLight(Color3f color,
                 Point3f position,
                 Point3f attenuation,
                 Vector3f direction,
                 float spreadAngle,
                 float concentration)

Constructs and initializes a SpotLight node using the specified parameters.

Parameters:

color - the color of the light source

position - the position of the light in three-space

attenuation - the attenuation (constant, linear, quadratic) of the light

direction - the direction of the light

spreadAngle - the spread angle of the light

concentration - the concentration of the light

SpotLight

public SpotLight(boolean lightOn,
                 Color3f color,
                 Point3f position,
                 Point3f attenuation,
                 Vector3f direction,
                 float spreadAngle,
                 float concentration)

Constructs and initializes a SpotLight node using the specified parameters.

Parameters:

lightOn - flag indicating whether this light is on or off

color - the color of the light source

position - the position of the light in three-space

attenuation - the attenuation (constant, linear, quadratic) of the light

direction - the direction of the light

spreadAngle - the spread angle of the light

concentration - the concentration of the light

Method Detail

setSpreadAngle

public void setSpreadAngle(float spreadAngle)

Sets spot light spread angle.

Parameters:

spreadAngle - the new spread angle for spot light

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph.

getSpreadAngle

public float getSpreadAngle()

Gets spot light spread angle.

Returns:

the new spread angle for spot light. The value returned is the clamped value.

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setConcentration

public void setConcentration(float concentration)

Sets spot light concentration.

Parameters:

concentration - the new concentration for spot light

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

getConcentration

public float getConcentration()

Gets spot light concentration.

Returns:

the new concentration for spot light

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setDirection

public void setDirection(float x,
                         float y,
                         float z)

Sets light direction.

Parameters:

x - the new X direction

y - the new Y direction

z - the new Z direction

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

setDirection

public void setDirection(Vector3f direction)

Sets this Light's current direction and places it in the parameter specified.

Parameters:

position - the vector that will receive this node's direction

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

getDirection

public void getDirection(Vector3f direction)

Gets this Light's current direction and places it in the parameter specified.

Parameters:

position - the vector that will receive this node's direction

Throws:

CapabilityNotSetException - if appropriate capability is not set and this object is part of live or compiled scene graph

cloneNode

public Node cloneNode(boolean forceDuplicate)

Used to create a new instance of the node. This routine is called by cloneTree to duplicate the current node.

Overrides:

cloneNode in class PointLight

Parameters:

forceDuplicate - when set to true, causes the duplicateOnCloneTree flag to be ignored. When false, the value of each node's duplicateOnCloneTree variable determines whether NodeComponent data is duplicated or copied.

See Also:

Node.cloneTree(), Node.cloneNode(boolean), Node.duplicateNode(javax.media.j3d.Node, boolean), NodeComponent.setDuplicateOnCloneTree(boolean)