man SoLight (Fonctions bibliothèques) -

NAME

SoLight -

SYNOPSIS



#include <Inventor/nodes/SoLight.h>

Inherits SoNode.

Inherited by SoDirectionalLight, SoPointLight, and SoSpotLight.

Detailed Description

The SoLight class is the base class for light emitting nodes.

This node type is abstract and does not in itself provide any light sources to the scene, you need to use one of its subclasses.

There are a few important things to know about light sources in Coin. First of all, the more light sources you have in your scene, the slower the rendering will be. The impact on rendering speed is highly dependent on the graphics hardware and/or rendering subsystem software implementation (i.e. how optimized an OpenGL you or your users are running), but it could be severe.

Another issue which is important to know is that OpenGL rendering engines usually have a fixed maximum number of available light sources which can be present in the state at the same time. If you reach the maximum number, further light sources will simply be ignored. The maximum number of light sources for OpenGL rendering can be found by using: 

      #include <Inventor/elements/SoGLLightIdElement.h>
#include <Inventor/nodes/SoSubNodeP.h>
      // ...[snip]...
      int nrlights = SoGLLightIdElement::getMaxGLSources();

If you are clever with how you use light sources, you can get away with using a lot more lights in a scene graph than the max available from the rendering system. This is because light sources are stacked on the traversal state, just like other appearance data. So if you put light sources under SoSeparator nodes, they will be popped off and 'forgotten' for the remaining geometry of the scene graph after the subgraph below an SoSeparator has been traversed.

Public Member Functions

virtual SoType getTypeId (void) const

virtual void callback (SoCallbackAction *action)

Static Public Member Functions

static SoType getClassTypeId (void)

static void initClass (void)

Public Attributes

SoSFBool on

SoSFFloat intensity

SoSFColor color

Protected Member Functions

virtual const SoFieldData * getFieldData (void) const

SoLight (void)

virtual ~SoLight ()

Static Protected Member Functions

static const SoFieldData ** getFieldDataPtr (void)

Constructor & Destructor Documentation

SoLight::SoLight (void) [protected]

Constructor.

SoLight::~SoLight () [protected, virtual]

Destructor.

Member Function Documentation

SoType SoLight::getClassTypeId (void) [static]

This static method returns the SoType object associated with objects of this class.

Reimplemented from SoNode.

Reimplemented in SoDirectionalLightManip, SoPointLightManip, SoSpotLightManip, SoDirectionalLight, SoPointLight, and SoSpotLight.

SoType SoLight::getTypeId (void) const [virtual]

Returns the type identification of an object derived from a class inheriting SoBase. This is used for run-time type checking and 'downward' casting.

Usage example: 

  void foo(SoNode * node)
  {
    if (node->getTypeId() == SoFile::getClassTypeId()) {
      SoFile * filenode = (SoFile *)node;  // safe downward cast, knows the type
    }
    else if (node->getTypeId().isOfType(SoGroup::getClassTypeId())) {
      SoGroup * group = (SoGroup *)node;  // safe downward cast, knows the type
    }
  }

For application programmers wanting to extend the library with new nodes, engines, nodekits, draggers or others: this method needs to be overridden in all subclasses. This is typically done as part of setting up the full type system for extension classes, which is usually accomplished by using the pre-defined macros available through for instance Inventor/nodes/SoSubNode.h (SO_NODE_INIT_CLASS and SO_NODE_CONSTRUCTOR for node classes), Inventor/engines/SoSubEngine.h (for engine classes) and so on.

For more information on writing Coin extensions, see the class documentation of the toplevel superclasses for the various class groups.

Implements SoBase.

Reimplemented in SoDirectionalLightManip, SoPointLightManip, SoSpotLightManip, SoDirectionalLight, SoPointLight, and SoSpotLight.

const SoFieldData ** SoLight::getFieldDataPtr (void) [static, protected]

This API member is considered internal to the library, as it is not likely to be of interest to the application programmer.

Reimplemented from SoNode.

Reimplemented in SoDirectionalLightManip, SoPointLightManip, SoSpotLightManip, SoDirectionalLight, SoPointLight, and SoSpotLight.

const SoFieldData * SoLight::getFieldData (void) const [protected, virtual]

Returns a pointer to the class-wide field data storage object for this instance. If no fields are present, returns NULL.

Reimplemented from SoFieldContainer.

Reimplemented in SoDirectionalLightManip, SoPointLightManip, SoSpotLightManip, SoDirectionalLight, SoPointLight, and SoSpotLight.

void SoLight::initClass (void) [static]

Sets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system.

Reimplemented from SoNode.

Reimplemented in SoDirectionalLightManip, SoPointLightManip, SoSpotLightManip, SoDirectionalLight, SoPointLight, and SoSpotLight.

void SoLight::callback (SoCallbackAction * action) [virtual]

Action method for SoCallbackAction.

Simply updates the state according to how the node behaves for the render action, so the application programmer can use the SoCallbackAction for extracting information about the scene graph.

Reimplemented from SoNode.

Reimplemented in SoDirectionalLightManip, SoPointLightManip, and SoSpotLightManip.

Member Data Documentation

SoSFBool SoLight::on

Whether light source should be on or off. The on-flag defaults to TRUE.

SoSFFloat SoLight::intensity

Intensity of light source. This decides how much the light source should affect the colors etc of the scene geometry. Valid range is 0.0 (none) to 1.0 (maximum). Default value is 1.0.

SoSFColor SoLight::color

Color of light source. Default is an all-white light source.

Author

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