Open Inventor Release 2024.1.1
 
Loading...
Searching...
No Matches
SoSpotLight Class Reference

Node representing a spotlight source. More...

#include <Inventor/nodes/SoSpotLight.h>

+ Inheritance diagram for SoSpotLight:

Public Member Functions

virtual SoType getTypeId () const
 Returns the type identifier for this specific instance.
 
 SoSpotLight ()
 Creates a spotlight source node with default settings.
 
- Public Member Functions inherited from SoNode
virtual void setOverride (const SbBool state)
 Turns the override flag on or off.
 
virtual SbBool isOverride () const
 Returns the state of the override flag.
 
virtual SoNodecopy (SbBool copyConnections=FALSE) const
 Creates and returns an exact copy of the node.
 
virtual SbBool affectsState () const
 Returns TRUE if a node has an effect on the state during traversal.
 
virtual void touch ()
 Marks an instance as modified, simulating a change to it.
 
- Public Member Functions inherited from SoFieldContainer
void setToDefaults ()
 Sets all fields in this object to their default values.
 
SbBool hasDefaultValues () const
 Returns TRUE if all of the object's fields have their default values.
 
SbBool fieldsAreEqual (const SoFieldContainer *fc) const
 Returns TRUE if this object's fields are exactly equal to fc's fields.
 
void copyFieldValues (const SoFieldContainer *fc, SbBool copyConnections=FALSE)
 Copies the contents of fc's fields into this object's fields.
 
SoNONUNICODE SbBool set (const char *fieldDataString)
 Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format.
 
SbBool set (const SbString &fieldDataString)
 Sets one or more fields in this object to the values specified in the given string, which should be a string in the Open Inventor file format.
 
void get (SbString &fieldDataString)
 Returns the values of the fields of this object in the Open Inventor ASCII file format in the given string.
 
virtual int getFields (SoFieldList &list) const
 Appends references to all of this object's fields to resultList, and returns the number of fields appended.
 
virtual int getAllFields (SoFieldList &list) const
 Returns a list of fields, including the eventIn's and eventOut's.
 
virtual SoFieldgetField (const SbName &fieldName) const
 Returns a the field of this object whose name is fieldName.
 
virtual SoFieldgetEventIn (const SbName &fieldName) const
 Returns a the eventIn with the given name.
 
virtual SoFieldgetEventOut (const SbName &fieldName) const
 Returns the eventOut with the given name.
 
SbBool getFieldName (const SoField *field, SbName &fieldName) const
 Returns the name of the given field in the fieldName argument.
 
SbBool enableNotify (SbBool flag)
 Notification at this Field Container is enabled (if flag == TRUE) or disabled (if flag == FALSE).
 
SbBool isNotifyEnabled () const
 Notification is the process of telling interested objects that this object has changed.
 
virtual void setUserData (void *data)
 Sets application data.
 
void * getUserData (void) const
 Gets user application data.
 
- Public Member Functions inherited from SoBase
virtual SbName getName () const
 Returns the name of an instance.
 
virtual void setName (const SbName &name)
 Sets the name of an instance.
 
void setSynchronizable (const bool b)
 Sets this to be a ScaleViz synchronizable object.
 
bool isSynchronizable () const
 Gets the ScaleViz synchronizable state of this object.
 
- Public Member Functions inherited from SoRefCounter
void ref () const
 Adds a reference to an instance.
 
void unref () const
 Removes a reference from an instance.
 
void unrefNoDelete () const
 unrefNoDelete() should be called when it is desired to decrement the reference count, but not delete the instance if this brings the reference count to zero.
 
int getRefCount () const
 Returns current reference count.
 
void lock () const
 lock this instance.
 
void unlock () const
 unlock this instance.
 
- Public Member Functions inherited from SoTypedObject
SbBool isOfType (const SoType &type) const
 Returns TRUE if this object is of the type specified in type or is derived from that type.
 
template<typename TypedObjectClass >
SbBool isOfType () const
 Returns TRUE if this object is of the type of class TypedObjectClass or is derived from that class.
 

Static Public Member Functions

static SoType getClassTypeId ()
 Returns the type identifier for this class.
 
- Static Public Member Functions inherited from SoLight
static SoType getClassTypeId ()
 Returns the type identifier for this class.
 
- Static Public Member Functions inherited from SoNode
static SoType getClassTypeId ()
 Returns the type identifier for this class.
 
static SoNodegetByName (const SbName &name)
 A node's name can be set using SoBase::setName().
 
static int getByName (const SbName &name, SoNodeList &list)
 A node's name can be set using SoBase::setName().
 
- Static Public Member Functions inherited from SoFieldContainer
static SoType getClassTypeId ()
 Returns the type of this class.
 
- Static Public Member Functions inherited from SoBase
static SoType getClassTypeId ()
 Returns type identifier for this class.
 
- Static Public Member Functions inherited from SoTypedObject
static SoType getClassTypeId ()
 Returns the type identifier for this class.
 

Public Attributes

SoSFVec3f location
 Location of the source.
 
SoSFVec3f direction
 Principal direction of illumination (center axis of cone).
 
SoSFFloat dropOffRate
 Rate of intensity drop-off per change in angle from primary direction: 0 = constant intensity, 1 = very sharp drop-off.
 
SoSFFloat cutOffAngle
 Angle (in radians) outside of which intensity is zero, measured from the center axis of the cone to an edge.
 
- Public Attributes inherited from SoLight
SoSFBool on
 Determines whether the source is active or inactive.
 
SoSFFloat intensity
 Illumination intensity of light source.
 
SoSFColor color
 Light source illumination color.
 

Detailed Description

Node representing a spotlight source.

This node defines a spotlight style light source. A spotlight is placed at a fixed location in 3-space and illuminates in a cone along a particular direction. The intensity of the illumination drops off exponentially as a ray of light diverges from this direction toward the edges of the cone. The rate of drop-off and the angle of the cone are controlled by the dropOffRate and cutOffAngle fields.

A light node defines an illumination source that may affect subsequent shapes in the scene graph, depending on the current lighting model. Light sources are affected by the current transformation. A light node under an SoSeparator does not affect any objects outside that separator. Lights may be grouped under an SoGroup node and still affect the rest of the scene graph. The viewer classes automatically create a directional light, called the headlight, that is automatically updated to shine in the same direction the camera is pointed.

You can also use a node kit to create a light. See the reference page for SoLightKit.

The lighting model can be changed using an SoLightModel node. Effectively lighting is enabled by default (default model is PER_VERTEX_PHONG), but can be turned off by setting the lighting model to BASE_COLOR. In this case the object's diffuse color is used without modification. This can be useful for axes and annotations.

An SoEnvironment node can be used to specify additional options related to lighting:

  • The ambient light component of the Phong reflection model.
  • Light attenuation for SoPointLight and SoSpotLight nodes.
  • Ambient occlusion.

When lighting is enabled, the appearance of most geometry depends on the normal vectors specified (or computed) for the geometry. See SoShapeHints for a discussion of normal computation and the concept of "crease angle". By default lighting is only computed for the "front" face of most geometry (there are some exceptions like SoOrthoSlice). Which face is the front depends on the vertex ordering. Also see SoShapeHints to control vertex ordering and to enable "two sided" lighting. Lighting of line geometry is affected by the tangent values, if any, specified with SoVertexProperty.

The color components specified for lights mean something different than for materials. For a light, the numbers correspond to a percentage of full intensity for each color. If the R, G, and B values for a light's color are all 1.0, the light is the brightest possible white. If the values are 0.5, the color is still white, but only at half intensity, so it appears gray. If R=G=1 and B=0 (full red and green with no blue), the light appears yellow. The intensity can also be modulated using the intensity field.

For materials, the numbers correspond to the reflected percentages of those colors. So if R=1, G=0.5, and B=0 for a material, that material reflects all the incoming red light, half the incoming green, and none of the incoming blue light. In other words, if an OpenGL light has components (LR, LG, LB), and a material has corresponding components (MR, MG, MB), then, ignoring all other reflectivity effects, the light that arrives at the eye is given by (LR*MR, LG*MG, LB*MB). As a result, for example, shining a pure blue light on a pure red cone has no visible effect.

Similarly, if you have two lights that send (R1, G1, B1) and (R2, G2, B2) to the eye, the components are added, giving (R1+R2, G1+G2, B1+B2). If any of the sums are greater than 1 (corresponding to a color brighter than the hardware can display), the component is clamped to 1.

The maximum number of lights depends on the hardware, but at least eight simultaneous lights are supported.

Note:
By default lighting is only computed at the vertices of the geometry and the resulting colors are interpolated across the geometry. As a result, the illumination cone of a spotlight may not be visible unless the geometry is highly tesselated.

FILE FORMAT/DEFAULT

    SpotLight {
    on TRUE
    intensity 1
    color 1 1 1
    location 0 0 1
    direction 0 0 -1
    dropOffRate 0
    cutOffAngle 0.785398
    }

ACTION BEHAVIOR

    SoGLRenderAction
    Activates this light (if so specified) during traversal. All shape nodes that come after this light in the scene graph are illuminated by this light. The light's location is affected by the current transformation. Sets: SoLightElement, SoLightIdElement

SEE ALSO

SoDirectionalLight, SoPointLight, SoLightModel

Definition at line 171 of file SoSpotLight.h.

Constructor & Destructor Documentation

◆ SoSpotLight()

SoSpotLight::SoSpotLight ( )

Creates a spotlight source node with default settings.

Member Function Documentation

◆ getClassTypeId()

static SoType SoSpotLight::getClassTypeId ( )
static

Returns the type identifier for this class.


◆ getTypeId()

virtual SoType SoSpotLight::getTypeId ( ) const
virtual

Returns the type identifier for this specific instance.

Reimplemented from SoLight.

Reimplemented in SoSpotLightManip.

Member Data Documentation

◆ cutOffAngle

SoSFFloat SoSpotLight::cutOffAngle

Angle (in radians) outside of which intensity is zero, measured from the center axis of the cone to an edge.

Definition at line 196 of file SoSpotLight.h.

◆ direction

SoSFVec3f SoSpotLight::direction

Principal direction of illumination (center axis of cone).

Definition at line 184 of file SoSpotLight.h.

◆ dropOffRate

SoSFFloat SoSpotLight::dropOffRate

Rate of intensity drop-off per change in angle from primary direction: 0 = constant intensity, 1 = very sharp drop-off.

Definition at line 190 of file SoSpotLight.h.

◆ location

SoSFVec3f SoSpotLight::location

Location of the source.

Definition at line 179 of file SoSpotLight.h.


The documentation for this class was generated from the following file: