Home | Hierarchy | Members | Alphabetical | Related Pages |
#include <spotlight.h>
Inherits Node.
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 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.
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
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.
See Detailed Description for meaning of this field. Default value is set to
ambientIntensity = 0.0f;
See Detailed Description for meaning of this field. Default value is set to
attenuation.setXYZ(1,0,0);
See Detailed Description for meaning of this field. Default value is set to
beamWidth = 1.5708f;
See Detailed Description for meaning of this field. Default value is set to
color.setRGB(1,1,1);
See Detailed Description for meaning of this field. Default value is set to
cutOffAngle = 0.785398f;
See Detailed Description for meaning of this field. Default value is set to
direction.setXYZ(0,0,-1);
See Detailed Description for meaning of this field. Default value is set to
intensity = 1.0f;
See Detailed Description for meaning of this field. Default value is set to
location.setXYZ(0,0,0);
See Detailed Description for meaning of this field. Default value is set to
on = true;
See Detailed Description for meaning of this field. Default value is set to
radius = 100.0f;
Set event associated to exposedField ambientIntensity
Set event associated to exposedField attenuation
Set event associated to exposedField beamWidth
Set event associated to exposedField cutOffAngle
Set event associated to exposedField direction
Set event associated to exposedField intensity
Set event associated to exposedField location
Set event associated to exposedField radius
Changed event associated to exposedField ambientIntensity
Changed event associated to exposedField attenuation
Changed event associated to exposedField beamWidth
Changed event associated to exposedField color
Changed event associated to exposedField cutOffAngle
Changed event associated to exposedField direction
Changed event associated to exposedField intensity
Changed event associated to exposedField location
Changed event associated to exposedField on
Changed event associated to exposedField radius
Generated on 5 Jan 2007 with
![]() |
|