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SpotLight Class Reference
[Standard Node Types]

#include <spotlight.h>

Inherits Node.

List of all members.

Public Member Functions

 SpotLight (const char *name="")
virtual ~SpotLight ()
virtual unsigned int nbFields () const
virtual FieldHandle field (const std::string &n)
virtual FieldHandle field (unsigned int i)
virtual bool isSetToDefaultValue (unsigned int i) const
virtual unsigned int nbEventsIn () const
virtual EventInHandle eventIn (const std::string &n)
virtual EventInHandle eventIn (unsigned int i)
virtual unsigned int nbEventsOut () const
virtual EventOutHandle eventOut (const std::string &n)
virtual EventOutHandle eventOut (unsigned int i)
const char * typeName () const
virtual Nodeduplicate () const
virtual Nodeduplicate (std::map< const Node *, Node * > &) const

Public Attributes

Exposed Fields
A field that is capable of receiving events via an eventIn to change its value(s), and generating events via an eventOut when its value(s) change.

SFFloat ambientIntensity
SFVec3f attenuation
SFFloat beamWidth
SFColor color
SFFloat cutOffAngle
SFVec3f direction
SFFloat intensity
SFVec3f location
SFBool on
SFFloat radius
Events In
EventIn< SFFloatset_ambientIntensity
EventIn< SFVec3fset_attenuation
EventIn< SFFloatset_beamWidth
EventIn< SFColorset_color
EventIn< SFFloatset_cutOffAngle
EventIn< SFVec3fset_direction
EventIn< SFFloatset_intensity
EventIn< SFVec3fset_location
EventIn< SFBoolset_on
EventIn< SFFloatset_radius
Events Out
EventOut< SFFloatambientIntensity_changed
EventOut< SFVec3fattenuation_changed
EventOut< SFFloatbeamWidth_changed
EventOut< SFColorcolor_changed
EventOut< SFFloatcutOffAngle_changed
EventOut< SFVec3fdirection_changed
EventOut< SFFloatintensity_changed
EventOut< SFVec3flocation_changed
EventOut< SFBoolon_changed
EventOut< SFFloatradius_changed


Detailed Description

Here is the documentation for this node type, from the ISO standard.

+6.64 SpotLight

The SpotLight node defines a light source that emits light from a specific point along a specific direction vector and constrained within a solid angle. Spotlights may illuminate geometry nodes that respond to light sources and intersect the solid angle defined by the SpotLight. Spotlight nodes are specified in the local coordinate system and are affected by ancestors' transformations.

A detailed description of ambientIntensity, color, intensity, and VRML's lighting equations is provided in 4.6.6, Light sources. More information on lighting concepts can be found in 4.14, Lighting model, including a detailed description of the VRML lighting equations.

The location field specifies a translation offset of the centre point of the light source from the light's local coordinate system origin. This point is the apex of the solid angle which bounds light emission from the given light source. The direction field specifies the direction vector of the light's central axis defined in the local coordinate system.

The on field specifies whether the light source emits light. If on is TRUE, the light source is emitting light and may illuminate geometry in the scene. If on is FALSE, the light source does not emit light and does not illuminate any geometry.

The radius field specifies the radial extent of the solid angle and the maximum distance from location that may be illuminated by the light source. The light source does not emit light outside this radius. The radius shall be greater than or equal to zero.

Both radius and location are affected by ancestors' transformations (scales affect radius and transformations affect location).

The cutOffAngle field specifies the outer bound of the solid angle. The light source does not emit light outside of this solid angle. The beamWidth field specifies an inner solid angle in which the light source emits light at uniform full intensity. The light source's emission intensity drops off from the inner solid angle (beamWidth) to the outer solid angle (cutOffAngle) as described in the following equations:

    angle = the angle between the Spotlight's direction vector
            and the vector from the Spotlight location to the point
            to be illuminated

    if (angle >= cutOffAngle):
        multiplier = 0
    else if (angle <= beamWidth):
        multiplier = 1
    else:
        multiplier = (angle - cutOffAngle) / (beamWidth - cutOffAngle)

    intensity(angle) = SpotLight.intensity × multiplier

If the beamWidth is greater than the cutOffAngle, beamWidth is defined to be equal to the cutOffAngle and the light source emits full intensity within the entire solid angle defined by cutOffAngle. Both beamWidth and cutOffAngle shall be greater than 0.0 and less than or equal to /2. Figure 6.16 depicts the beamWidth, cutOffAngle, direction, location, and radius fields of the SpotLight node.

SpotLight node

Figure 6.16 -- SpotLight node

SpotLight illumination falls off with distance as specified by three attenuation coefficients. The attenuation factor is 1/max(attenuation[0] + attenuation[1]×r + attenuation[2]×r2 , 1), where r is the distance from the light to the surface being illuminated. The default is no attenuation. An attenuation value of (0, 0, 0) is identical to (1, 0, 0). Attenuation values shall be greater than or equal to zero. A detailed description of VRML's lighting equations is contained in 4.14, Lighting model.

--- VRML separator bar ---


Constructor & Destructor Documentation

SpotLight ( const char *  name = ""  ) 

Construct a node with all its fields set to default value, which is equivalent to the code below:

  ambientIntensity = 0.0f;
  attenuation.setXYZ(1,0,0);
  beamWidth = 1.5708f;
  color.setRGB(1,1,1);
  cutOffAngle = 0.785398f;
  direction.setXYZ(0,0,-1);
  intensity = 1.0f;
  location.setXYZ(0,0,0);
  on = true;
  radius = 100.0f;

~SpotLight (  )  [virtual]

Virtual destructor, does nothing


Member Function Documentation

unsigned int nbFields (  )  const [inline, virtual]

Returns the number of fields (exposed or not) for this node type.

Implements Node.

wrl::Node::FieldHandle field ( const std::string &  n  )  [virtual]

Return a handle on the field named n of the node or a "unknown" typed handle if there is no such field. Valid names are:

Implements Node.

wrl::Node::FieldHandle field ( unsigned int  n  )  [virtual]

Return a handle on the i th field of the node or a "unknown" typed handle if there is no such node. Here is how i is related to fields:

Implements Node.

bool isSetToDefaultValue ( unsigned int  i  )  const [virtual]

Implements Node.

unsigned int nbEventsIn (  )  const [inline, virtual]

Returns the number of events in for this node type.

Implements Node.

wrl::Node::EventInHandle eventIn ( const std::string &  n  )  [virtual]

Return a handle on the event in named n of the node or a "unknown" typed handle if there is no such event. Valid names are:

Implements Node.

wrl::Node::EventInHandle eventIn ( unsigned int  n  )  [virtual]

Return a handle on the i th event in of the node or a "unknown" typed handle if there is no such node. emarks This class has no eventIn. This function is useful, with nbEventsIn() if you want to traverse all events in of a Node.

Implements Node.

unsigned int nbEventsOut (  )  const [inline, virtual]

Returns the number of events out for this node type.

Implements Node.

wrl::Node::EventOutHandle eventOut ( const std::string &  n  )  [virtual]

Return a handle on the event out named n of the node or a "unknown" typed handle if there is no such event. Valid names are:

Implements Node.

wrl::Node::EventOutHandle eventOut ( unsigned int  n  )  [virtual]

Return a handle on the i th event out of the node or a "unknown" typed handle if there is no such node. Here is how i is related to fields:

Implements Node.

const char * typeName (  )  const [inline, virtual]

Returns "SpotLight". Useful for printing.

Implements Node.

wrl::Node * duplicate (  )  const [virtual]

Returns a deep copy of this node, that is a fully independant node with all children (if any) also copied. This is mainly useful for instanciating protos.

Implements Node.

virtual Node* duplicate ( std::map< const Node *, Node * > &   )  const [virtual]

Implements Node.


Member Data Documentation

SFFloat ambientIntensity

See Detailed Description for meaning of this field. Default value is set to

SFVec3f attenuation

See Detailed Description for meaning of this field. Default value is set to

       attenuation.setXYZ(1,0,0);

SFFloat beamWidth

See Detailed Description for meaning of this field. Default value is set to

       beamWidth = 1.5708f;

SFColor color

See Detailed Description for meaning of this field. Default value is set to

       color.setRGB(1,1,1);

SFFloat cutOffAngle

See Detailed Description for meaning of this field. Default value is set to

       cutOffAngle = 0.785398f;

SFVec3f direction

See Detailed Description for meaning of this field. Default value is set to

       direction.setXYZ(0,0,-1);

SFFloat intensity

See Detailed Description for meaning of this field. Default value is set to

       intensity = 1.0f;

SFVec3f location

See Detailed Description for meaning of this field. Default value is set to

       location.setXYZ(0,0,0);

SFBool on

See Detailed Description for meaning of this field. Default value is set to

       on = true;

SFFloat radius

See Detailed Description for meaning of this field. Default value is set to

       radius = 100.0f;

EventIn<SFFloat> set_ambientIntensity

Set event associated to exposedField ambientIntensity

EventIn<SFVec3f> set_attenuation

Set event associated to exposedField attenuation

EventIn<SFFloat> set_beamWidth

Set event associated to exposedField beamWidth

EventIn<SFColor> set_color

Set event associated to exposedField color

EventIn<SFFloat> set_cutOffAngle

Set event associated to exposedField cutOffAngle

EventIn<SFVec3f> set_direction

Set event associated to exposedField direction

EventIn<SFFloat> set_intensity

Set event associated to exposedField intensity

EventIn<SFVec3f> set_location

Set event associated to exposedField location

EventIn<SFBool> set_on

Set event associated to exposedField on

EventIn<SFFloat> set_radius

Set event associated to exposedField radius

EventOut<SFFloat> ambientIntensity_changed

Changed event associated to exposedField ambientIntensity

EventOut<SFVec3f> attenuation_changed

Changed event associated to exposedField attenuation

EventOut<SFFloat> beamWidth_changed

Changed event associated to exposedField beamWidth

EventOut<SFColor> color_changed

Changed event associated to exposedField color

EventOut<SFFloat> cutOffAngle_changed

Changed event associated to exposedField cutOffAngle

EventOut<SFVec3f> direction_changed

Changed event associated to exposedField direction

EventOut<SFFloat> intensity_changed

Changed event associated to exposedField intensity

EventOut<SFVec3f> location_changed

Changed event associated to exposedField location

EventOut<SFBool> on_changed

Changed event associated to exposedField on

EventOut<SFFloat> radius_changed

Changed event associated to exposedField radius


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