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Vrml


Vrml_ShapeHints Class Reference

defines a ShapeHints node of VRML specifying properties of geometry and its appearance.
The ShapeHints node indicates that IndexedFaceSets are solid, contain ordered vertices, or
contain convex faces.
These hints allow VRML implementations to optimize certain rendering features.
Optimizations that may be performed include enabling back-face culling and disabling
two-sided lighting. For example, if an object is solid and has ordered vertices, an
implementation may turn on backface culling and turn off two-sided lighting. To ensure
that an IndexedFaceSet can be viewed from either direction, set shapeType to be
UNKNOWN_SHAPE_TYPE.
If you know that your shapes are closed and will alwsys be viewed from the outside, set
vertexOrdering to be either CLOCKWISE or COUNTERCLOCKWISE (depending on
how you built your object), and set shapeType to be SOLID. Placing this near the top of
your VRML file will allow the scene to be rendered much faster.
The ShapeHints node also affects how default normals are generated. When an
IndexedFaceSet has to generate default normals, it uses the creaseAngle field to determine
which edges should be smoothly shaded and which ones should have a sharp crease. The
crease angle is the angle between surface normals on adjacent polygons. For example, a
crease angle of .5 radians (the default value) means that an edge between two adjacent
polygonal faces will be smooth shaded if the normals to the two faces form an angle that is
less than .5 radians (about 30 degrees). Otherwise, it will be faceted.

#include <Vrml_ShapeHints.hxx>


Public Member Functions

void * operator new (size_t, void *anAddress)
void * operator new (size_t size)
void operator delete (void *anAddress)
Standard_EXPORT Vrml_ShapeHints (const Vrml_VertexOrdering aVertexOrdering=Vrml_UNKNOWN_ORDERING, const Vrml_ShapeType aShapeType=Vrml_UNKNOWN_SHAPE_TYPE, const Vrml_FaceType aFaceType=Vrml_CONVEX, const Standard_Real aAngle=0.5)
Standard_EXPORT void SetVertexOrdering (const Vrml_VertexOrdering aVertexOrdering)
Standard_EXPORT Vrml_VertexOrdering VertexOrdering () const
Standard_EXPORT void SetShapeType (const Vrml_ShapeType aShapeType)
Standard_EXPORT Vrml_ShapeType ShapeType () const
Standard_EXPORT void SetFaceType (const Vrml_FaceType aFaceType)
Standard_EXPORT Vrml_FaceType FaceType () const
Standard_EXPORT void SetAngle (const Standard_Real aAngle)
Standard_EXPORT Standard_Real Angle () const
Standard_EXPORT Standard_OStream & Print (Standard_OStream &anOStream) const

Private Attributes

Vrml_VertexOrdering myVertexOrdering
Vrml_ShapeType myShapeType
Vrml_FaceType myFaceType
Standard_Real myAngle


Constructor & Destructor Documentation

Standard_EXPORT Vrml_ShapeHints::Vrml_ShapeHints const Vrml_VertexOrdering  aVertexOrdering = Vrml_UNKNOWN_ORDERING,
const Vrml_ShapeType  aShapeType = Vrml_UNKNOWN_SHAPE_TYPE,
const Vrml_FaceType  aFaceType = Vrml_CONVEX,
const Standard_Real  aAngle = 0.5
 


Member Function Documentation

Standard_EXPORT Standard_Real Vrml_ShapeHints::Angle  )  const
 

Standard_EXPORT Vrml_FaceType Vrml_ShapeHints::FaceType  )  const
 

void Vrml_ShapeHints::operator delete void *  anAddress  )  [inline]
 

void* Vrml_ShapeHints::operator new size_t  size  )  [inline]
 

void* Vrml_ShapeHints::operator new size_t  ,
void *  anAddress
[inline]
 

Standard_EXPORT Standard_OStream& Vrml_ShapeHints::Print Standard_OStream &  anOStream  )  const
 

Standard_EXPORT void Vrml_ShapeHints::SetAngle const Standard_Real  aAngle  ) 
 

Standard_EXPORT void Vrml_ShapeHints::SetFaceType const Vrml_FaceType  aFaceType  ) 
 

Standard_EXPORT void Vrml_ShapeHints::SetShapeType const Vrml_ShapeType  aShapeType  ) 
 

Standard_EXPORT void Vrml_ShapeHints::SetVertexOrdering const Vrml_VertexOrdering  aVertexOrdering  ) 
 

Standard_EXPORT Vrml_ShapeType Vrml_ShapeHints::ShapeType  )  const
 

Standard_EXPORT Vrml_VertexOrdering Vrml_ShapeHints::VertexOrdering  )  const
 


Field Documentation

Standard_Real Vrml_ShapeHints::myAngle [private]
 

Vrml_FaceType Vrml_ShapeHints::myFaceType [private]
 

Vrml_ShapeType Vrml_ShapeHints::myShapeType [private]
 

Vrml_VertexOrdering Vrml_ShapeHints::myVertexOrdering [private]
 


The documentation for this class was generated from the following file:
Generated on Mon Aug 25 14:46:07 2008 for OpenCASCADE by  doxygen 1.4.1