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SoClipPlane.3sim

NAME

SoClipPlane - The SoClipPlane class is a node type for specifying clipping planes.

A scene graph without any SoClipPlane nodes uses six clipping planes to define the viewing frustum: top, bottom, left, right, near and far. If you want extra clipping planes for 'slicing' the visible geometry, you can do that by using nodes of this type. Geometry on the back side of the clipping plane is clipped away.

SYNOPSIS

#include <Inventor/nodes/SoClipPlane.h>

Inherits SoNode.

Inherited by SoClipPlaneManip.

Public Member Functions

virtual SoType getTypeId (void) const

SoClipPlane (void)

virtual void doAction (SoAction *action)

virtual void GLRender (SoGLRenderAction *action)

virtual void callback (SoCallbackAction *action)

virtual void pick (SoPickAction *action)

Static Public Member Functions

static SoType getClassTypeId (void)

static void initClass (void)

Public Attributes

SoSFPlane plane

SoSFBool on

Protected Member Functions

virtual const SoFieldData * getFieldData (void) const

virtual ~SoClipPlane ()

Static Protected Member Functions

static const SoFieldData ** getFieldDataPtr (void)

Detailed Description

The SoClipPlane class is a node type for specifying clipping planes.

A scene graph without any SoClipPlane nodes uses six clipping planes to define the viewing frustum: top, bottom, left, right, near and far. If you want extra clipping planes for 'slicing' the visible geometry, you can do that by using nodes of this type. Geometry on the back side of the clipping plane is clipped away.

Note that OpenGL implementations have a fixed maximum number of clipping planes available. To find out what this number is, you can use the following code:

       #include <Inventor/elements/SoGLClipPlaneElement.h>
       // ...[snip]...
       int maxplanes = SoGLClipPlaneElement::getMaxGLPlanes();
 

Below is a simple, basic scene graph usage example of SoClipPlane. It connects an SoClipPlane to an SoCenterballDragger, for end-user control over the orientation and position of the clipping plane:

 
   #Inventor V2.1 ascii
   
   Separator {
      Separator {
         Translation { translation -6 0 0 }
         DEF cbdragger CenterballDragger { }
      }
   
      TransformSeparator {
         Transform {
            rotation 0 0 1 0 = USE cbdragger . rotation
            translation 0 0 0 = USE cbdragger . center
         }
         ClipPlane { }
      }
   
      Sphere { }
   }
   .fi
 
 
 Note that SoClipPlane is a state-changing appearance node, and as such, it will only assert its effects under the current SoSeparator node (as the SoSeparator pops the state stack when traversal returns above it), as can be witnessed by loading this simple example file into a Coin viewer:
 
 
 
   #Inventor V2.1 ascii
   
   Separator {
      ClipPlane { }
      Cube { }
   }
   
   Separator {
      Translation { translation -3 0 0 }
      Cube { }
   }
   .fi
 
 
 FILE FORMAT/DEFAULTS: 
 
     ClipPlane {
         plane 1 0 0  0
         on TRUE
     }
 
 

 

Constructor & Destructor Documentation

SoClipPlane::SoClipPlane (void)

Constructor.

References on, and plane.

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

Destructor.

Member Function Documentation

SoType SoClipPlane::getClassTypeId (void) [static]

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

Reimplemented from SoNode.

Reimplemented in SoClipPlaneManip.

Referenced by SoClipPlaneManip::replaceNode().

SoType SoClipPlane::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 SoClipPlaneManip.

const SoFieldData ** SoClipPlane::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 SoClipPlaneManip.

const SoFieldData * SoClipPlane::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 SoClipPlaneManip.

void SoClipPlane::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 SoClipPlaneManip.

void SoClipPlane::doAction (SoAction * action) [virtual]

This function performs the typical operation of a node for any action.

Reimplemented from SoNode.

Reimplemented in SoClipPlaneManip.

References SoAction::getState(), SoSFPlane::getValue(), SoSFBool::getValue(), SoField::isIgnored(), on, and plane.

Referenced by callback(), GLRender(), and pick().

void SoClipPlane::GLRender (SoGLRenderAction * action) [virtual]

Action method for the SoGLRenderAction.

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.

Reimplemented from SoNode.

Reimplemented in SoClipPlaneManip.

References doAction(), SoAction::getState(), SoSFPlane::getValue(), SoSFBool::getValue(), SoField::isIgnored(), on, plane, and SbPlane::transform().

void SoClipPlane::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 SoClipPlaneManip.

References doAction().

void SoClipPlane::pick (SoPickAction * action) [virtual]

Action method for SoPickAction.

Does common processing for SoPickAction action instances.

Reimplemented from SoNode.

Reimplemented in SoClipPlaneManip.

References doAction().

Member Data Documentation

SoSFPlane SoClipPlane::plane

Definition of clipping plane. Geometry on the back side of the clipping plane is clipped away.

The default clipping plane has it's normal pointing in the <1,0,0> direction, and intersects origo. (I.e., everything along the negative X axis is clipped.)

Referenced by doAction(), SoClipPlaneManip::fieldSensorCB(), GLRender(), SoClipPlaneManip::setValue(), SoClipPlane(), SoClipPlaneManip::transferFieldValues(), and SoClipPlaneManip::valueChangedCB().

SoSFBool SoClipPlane::on

Whether clipping plane should be on or off. Defaults to TRUE.

Referenced by doAction(), GLRender(), SoClipPlane(), and SoClipPlaneManip::transferFieldValues().

Author

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