Node that defines the lighting model to use when rendering. More...

#include <Inventor/nodes/SoLightModel.h>

Inheritance diagram for SoLightModel:

Public Types
enum	Model { BASE_COLOR = SoLightModelElement::BASE_COLOR , PHONG = SoLightModelElement::PHONG , PER_VERTEX_PHONG = SoLightModelElement::PER_VERTEX_PHONG , PER_PIXEL_PHONG = SoLightModelElement::PER_PIXEL_PHONG , PHYSICALLY_BASED = SoLightModelElement::PHYSICALLY_BASED }
	Lighting model. More...

Public Member Functions
virtual SoType	getTypeId () const
	Returns the type identifier for this specific instance.

	SoLightModel ()
	Creates a light model node with default settings.

virtual void	setOverride (const SbBool state)
	Set the state of the override field.

virtual SbBool	isOverride () const
	Returns the state of the override field.

Public Member Functions inherited from SoNode
virtual SoNode *	copy (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 SoField *	getField (const SbName &fieldName) const
	Returns a the field of this object whose name is fieldName.

virtual SoField *	getEventIn (const SbName &fieldName) const
	Returns a the eventIn with the given name.

virtual SoField *	getEventOut (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 SoNode
static SoType	getClassTypeId ()
	Returns the type identifier for this class.

static SoNode *	getByName (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
SoSFEnum	model
	Lighting model to use Use enum Model.

Detailed Description

Node that defines the lighting model to use when rendering.

This node defines the lighting model to use when rendering subsequent shapes. The lighting model is specified in the model field, which is PER_VERTEX_PHONG by default.

SoLightModel supports several types of light model. The following images provide examples of rendering the same scene using a different light model.

BASE_COLOR

PER_PIXEL_PHONG

PHYSICALLY_BASED

When the light model is not BASE_COLOR, there must be light nodes (e.g. SoDirectionalLight) in the scene graph for objects to be easily visible. When using the Open Inventor viewer classes (e.g. SoWinExaminerViewer), the viewer will create a "headlight" (directional light attached to the camera) if no other light nodes exist when setSceneGraph() is called. When using the Open Inventor viewer components (e.g. SceneExaminer), a "headlight" is automatically added to the scene graph.

You can use a SoEnvironment node to specify additional lighting options:

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

Definition of base color

All the light models supported by Open Inventor use the concept of base color composed of 3 channels red green blue (rgb). It corresponds to the color of an object before being altered by light effects. Unfortunatly the term base color is not always used in the API and documentation, sometimes it is referred to as diffuse color, rgb color*, a rgb or just color.

The following fields define the same concept of base color of an object:

The following C++ code samples are equivalent and define a single red opaque base color:

// using SoMaterial
mySoMaterial->diffuseColor = SbColor(1,0,0);
mySoMaterial->transparency = 0 ;
 
// using SoPhysicalMaterial
mySoPhysicalMaterial->baseColor = SbColorRGBA(1,0,0,1);
 
// using SoBaseColor
mySoBaseColor->rgb = SbColor(1,0,0);
 
// using SoPackedColor
mySoPackedColor->orderedRGBA = SbColorRGBA(1,0,0,1).getPackedValue();
 
// using SoColorMap
mySoColorMap->colorMap.setValues(0, 4, new float[4]{ 1, 0, 0, 1 });
 
// using SoBufferedShape
mySoBufferedShape->colorBuffer = new SoCpuBufferObject(new float[4]{ 1, 0, 0, 1 }, 4 * sizeof(float));
 
// using SoVertexProperty
mySoVertexProperty->orderedRGBA = SbColorRGBA(1,0,0,1).getPackedValue();

Changing the value of any of those fields overrides the base color of an object. This means that if you set 2 different fields to specify a color, the current definition of a color during the scene graph traversal overrides the previous one. For instance, the following code sample specifies an opaque red color that overrides the semi opaque green.

mySoPhysicalMaterial->baseColor = SbColorRGBA(0,1,0,0.5f); // semi opaque green color
mySoMaterial->diffuseColor = SbColor(1,0,0); // red color
mySoMaterial->transparency = 0 ;
myRoot->addChild(mySoPhysicalMaterial);
myRoot->addChild(mySoMaterial); // this red material overrides the green color

Light model and property nodes

According to the light model selected, the following notes explain what is taken into account in the scene graph, and what is ignored:

Using model BASE_COLOR

Objects are drawn using the base color only. There is no lighting.
If a node related to the material is visited after SoBaseColor during the traversal, the rgb defined by the SoBaseColor may change.
The base color is specified as described above.
The SoMaterial fields are ignored except diffuseColor and transparency.
The SoPhysicalMaterial fields are ignored except baseColor.
The SoLight instances are ignored.
The SoEnvironment instances are ignored.

Using PER_VERTEX_PHONG or PER_PIXEL_PHONG

The lighting takes into account all fields of SoMaterial.
If a node related to the material is visited after the SoMaterial during the traversal, the diffuseColor and transparency defined by the SoMaterial may change
The base color is specified as described above.
The SoPhysicalMaterial fields are ignored except baseColor.
The SoLight instances are used.
The SoEnvironment instances are used.

Using PHYSICALLY_BASED

The lighting takes into account all fields of SoPhysicalMaterial.
If a node related to the material is visited after the SoPhysicalMaterial during the traversal, the baseColor defined by the SoPhysicalMaterial may change
The base color is specified as described above.
The SoMaterial fields are ignored except diffuseColor and transparency.
The SoLight instances are used.
The SoEnvironment instances are used.

Two side lighting

By default, lighting is only computed for the "front" faces of the geometry, leaving the back face of the geometry dark. If the normal vector is specified, it determines the front face. If normals are computed by Open Inventor, the vertex ordering (see SoShapeHints) determines the front face. To enable "two sided" lighting (lighting both front and back faces) see SoShapeHints.

Light model and VolumeViz

The SoLightModel node controls lighting for most VolumeViz shapes, but not for SoVolumeRender. The lighting for volume rendering is controlled by the SoVolumeRenderingQuality node.

Two sided lighting is automatically enabled for "slice" shapes, such as SoOrthoSlice.

FILE FORMAT/DEFAULT

model

PER_VERTEX_PHONG

ACTION BEHAVIOR

SoGLRenderAction

SoCallbackAction

Member Enumeration Documentation

◆ Model

enum SoLightModel::Model

Lighting model.

Enumerator
BASE_COLOR	Use only the base color of an object. Effectively lighting is turned off and light nodes are not considered. This mode is adapted to render annotation, for data visualization, for 2D scenes, and other special cases.
PHONG	Use Phong lighting model.
PER_VERTEX_PHONG	Use the Vertex-based Phong lighting model (default). Lighting is computed at each vertex of the shape and the color of each pixel (fragment) is determined by interpolating between these values. This model produces less realistic results than pixel-based lighting, especially for Point and Spot lights.
PER_PIXEL_PHONG	Use the Pixel-based Phong lighting model. A lighting computation is done for each pixel (fragment) affected by the shape.
PHYSICALLY_BASED	Use the physically based lighting model.

Definition at line 251 of file SoLightModel.h.

Constructor & Destructor Documentation

◆ SoLightModel()

SoLightModel::SoLightModel ( )

Creates a light model node with default settings.

Member Function Documentation

◆ getClassTypeId()

static SoType SoLightModel::getClassTypeId ( )

static

Returns the type identifier for this class.

◆ getTypeId()

virtual SoType SoLightModel::getTypeId ( ) const

virtual

Returns the type identifier for this specific instance.

Reimplemented from SoNode.

◆ isOverride()

virtual SbBool SoLightModel::isOverride ( ) const

inlinevirtual

Returns the state of the override field.

Reimplemented from SoNode.

Definition at line 303 of file SoLightModel.h.

◆ setOverride()

virtual void SoLightModel::setOverride ( const SbBool state )

inlinevirtual

Set the state of the override field.

see SoNode::setOverride doc.

Reimplemented from SoNode.

Definition at line 297 of file SoLightModel.h.

Member Data Documentation

◆ model

SoSFEnum SoLightModel::model

Lighting model to use Use enum Model.

Default is PER_VERTEX_PHONG.

Definition at line 286 of file SoLightModel.h.

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

Inventor/nodes/SoLightModel.h

Open Inventor Release 2024.2.0

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes

Detailed Description

Definition of base color

Light model and property nodes

Two side lighting

Light model and VolumeViz

FILE FORMAT/DEFAULT

ACTION BEHAVIOR

SEE ALSO

Member Enumeration Documentation

◆ Model

Constructor & Destructor Documentation

◆ SoLightModel()

Member Function Documentation

◆ getClassTypeId()

◆ getTypeId()

◆ isOverride()

◆ setOverride()

Member Data Documentation

◆ model