.TH "SoDirectionalLight" 3 "Sat Oct 12 2013" "Version 4.0.0a" "Coin" \" -*- nroff -*-
.ad l
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.SH NAME
SoDirectionalLight \- 
.PP
The \fBSoDirectionalLight\fP class is a node type for specifying directional light sources\&.
.PP
A directional light source provides a model of light sources which are at infinite distance from the geometry it illuminates, thereby having no set position and consisting of an infinite volume of parallel rays\&.  

.SH SYNOPSIS
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.PP
.PP
\fC#include <Inventor/nodes/SoDirectionalLight\&.h>\fP
.PP
Inherits \fBSoLight\fP\&.
.PP
Inherited by \fBSoDirectionalLightManip\fP, and \fBSoShadowDirectionalLight\fP\&.
.SS "Public Member Functions"

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.RI "virtual \fBSoType\fP \fBgetTypeId\fP (void) const "
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.RI "\fIReturns the type identification of an object derived from a class inheriting \fBSoBase\fP\&. This is used for run-time type checking and 'downward' casting\&. \fP"
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.RI "\fBSoDirectionalLight\fP (void)"
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.RI "virtual void \fBGLRender\fP (\fBSoGLRenderAction\fP *action)"
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.SS "Static Public Member Functions"

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.RI "static \fBSoType\fP \fBgetClassTypeId\fP (void)"
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.RI "\fIThis static method returns the \fBSoType\fP object associated with objects of this class\&. \fP"
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.RI "static void \fBinitClass\fP (void)"
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.RI "\fISets up initialization for data common to all instances of this class, like submitting necessary information to the Coin type system\&. \fP"
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.SS "Public Attributes"

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.RI "\fBSoSFVec3f\fP \fBdirection\fP"
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.SS "Protected Member Functions"

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.RI "virtual const \fBSoFieldData\fP * \fBgetFieldData\fP (void) const "
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.RI "virtual \fB~SoDirectionalLight\fP ()"
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.SS "Static Protected Member Functions"

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.RI "static const \fBSoFieldData\fP ** \fBgetFieldDataPtr\fP (void)"
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.SS "Additional Inherited Members"
.SH "Detailed Description"
.PP 
The \fBSoDirectionalLight\fP class is a node type for specifying directional light sources\&.
.PP
A directional light source provides a model of light sources which are at infinite distance from the geometry it illuminates, thereby having no set position and consisting of an infinite volume of parallel rays\&. 

This is of course a simplified model of far-away light sources, as 'infinite distance' is impossible\&.
.PP
The sun shining on objects on earth is a good example of something which can be modeled rather well for the most common purposes with a directional light source\&.
.PP
See also documentation of parent class for important information regarding light sources in general\&.
.PP
\fBFILE FORMAT/DEFAULTS:\fP 
.PP
.nf
DirectionalLight {
    on TRUE
    intensity 1
    color 1 1 1
    direction 0 0 -1
}

.fi
.PP
.PP
A common thing to do with an \fBSoDirectionalLight\fP is to connect it to a camera, so it works in the style of a head light to that camera\&. This can easily be accomplished by linking an \fBSoRotation::rotation\fP field, influencing the light, to the \fBSoCamera::orientation\fP field\&. Here is a complete example iv-file demonstrating the technique:
.PP
.PP
.nf
#Inventor V2.1 ascii

DEF mycam PerspectiveCamera { }

TransformSeparator {
   SoRotation { rotation = USE mycam.orientation }
   DirectionalLight { direction 0 0 -1 }
}

Cube { }
.fi
.PP
.PP
(The \fBSoTransformSeparator\fP is included to keep the effect of the \fBSoRotation\fP node within a scope where it will only influence the light, and not the geometry following the light in the scene graph\&.) 
.SH "Constructor & Destructor Documentation"
.PP 
.SS "SoDirectionalLight::SoDirectionalLight (void)"
Constructor\&. 
.SS "SoDirectionalLight::~SoDirectionalLight ()\fC [protected]\fP, \fC [virtual]\fP"
Destructor\&. 
.SH "Member Function Documentation"
.PP 
.SS "\fBSoType\fP SoDirectionalLight::getTypeId (void) const\fC [virtual]\fP"

.PP
Returns the type identification of an object derived from a class inheriting \fBSoBase\fP\&. This is used for run-time type checking and 'downward' casting\&. Usage example:
.PP
.PP
.nf
void foo(SoNode * node)
{
  if (node->getTypeId() == SoFile::getClassTypeId()) {
    SoFile * filenode = (SoFile *)node;  // safe downward cast, knows the type
  }
}
.fi
.PP
.PP
For application programmers wanting to extend the library with new nodes, engines, nodekits, draggers or others: this method needs to be overridden in \fIall\fP 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 \fBInventor/nodes/SoSubNode\&.h\fP (SO_NODE_INIT_CLASS and SO_NODE_CONSTRUCTOR for node classes), Inventor/engines/SoSubEngine\&.h (for engine classes) and so on\&.
.PP
For more information on writing Coin extensions, see the class documentation of the toplevel superclasses for the various class groups\&. 
.PP
Reimplemented from \fBSoLight\fP\&.
.PP
Reimplemented in \fBSoDirectionalLightManip\fP, and \fBSoShadowDirectionalLight\fP\&.
.SS "const \fBSoFieldData\fP ** SoDirectionalLight::getFieldDataPtr (void)\fC [static]\fP, \fC [protected]\fP"
\fIThis API member is considered internal to the library, as it is not likely to be of interest to the application programmer\&.\fP 
.PP
Reimplemented from \fBSoLight\fP\&.
.PP
Reimplemented in \fBSoDirectionalLightManip\fP, and \fBSoShadowDirectionalLight\fP\&.
.SS "const \fBSoFieldData\fP * SoDirectionalLight::getFieldData (void) const\fC [protected]\fP, \fC [virtual]\fP"
Returns a pointer to the class-wide field data storage object for this instance\&. If no fields are present, returns \fCNULL\fP\&. 
.PP
Reimplemented from \fBSoLight\fP\&.
.PP
Reimplemented in \fBSoDirectionalLightManip\fP, and \fBSoShadowDirectionalLight\fP\&.
.SS "void SoDirectionalLight::GLRender (\fBSoGLRenderAction\fP *action)\fC [virtual]\fP"
Action method for the \fBSoGLRenderAction\fP\&.
.PP
This is called during rendering traversals\&. Nodes influencing the rendering state in any way or who wants to throw geometry primitives at OpenGL overrides this method\&. 
.PP
Reimplemented from \fBSoNode\fP\&.
.PP
Reimplemented in \fBSoDirectionalLightManip\fP, and \fBSoShadowDirectionalLight\fP\&.
.SH "Member Data Documentation"
.PP 
.SS "\fBSoSFVec3f\fP SoDirectionalLight::direction"
The direction of the light source\&. Defaults to pointing along the negative z-axis\&. 

.SH "Author"
.PP 
Generated automatically by Doxygen for Coin from the source code\&.