Extract data from an SoVolumeRender More...

#include <VolumeViz/nodes/SoOffscreenVolumeRender.h>

Inheritance diagram for SoOffscreenVolumeRender:

Public Types
enum	Components { ALPHA , RGBA }

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

	SoOffscreenVolumeRender ()
	Default constructor.

SbVec3i32	getMaxBoxSize (SoState *state=NULL)
	Returns the maximum boxSize that can be extract in one boxComputed for the current state.

SbBox3d	ijkToXyzBox (const SbBox3i32 &ijkBox)
	Convert ijk box coordinates returned by boxComputed method to the bboxSceneGraph space.

bool	synchronousExtraction (SoSceneManager *sceneManager)
	Does extraction synchronously, whereas using trigger field will execute extraction on next redraw.

Public Member Functions inherited from SoNode
virtual void	setOverride (const SbBool state)
	Turns the override flag on or off.

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

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
SoSFNode	volumerenderSceneGraph
	Head of the scene graph that contains one or multiple VolumeRender node to render in 3D off-screen cube.

SoSFNode	bboxSceneGraph
	Head of the scene graph that defines the 3D off-screen scene cube to consider in world coordinates.

SoSFVec3i32	boxSize
	Resolution of the output data in the off-screen box.

SoSFBool	trigger
	Setting this field to TRUE will start the off-screen rendering process.

SoSFFloat	opacityThreshold
	During extraction, voxels with an opacity less than the specified value will be ignored Default is 0.

SoSFEnum	components
	Components to get back from the offscreen render.

SoSFMatrix	dataSpaceMatrix
	This transformation is applied on the volume render texture coordinate during the extraction.

Detailed Description

Extract data from an SoVolumeRender

The SoOffscreenVolumeRender node extracts data by rendering one or more volumes (via SoVolumeRender) into a buffer that can then be used for different computation tasks.

Volumes of interest are specified by a subscenegraph in volumerenderSceneGraph.

The region to be extracted is the bounding box of the scene graph specified in the bboxSceneGraph field.

To implement an extraction, the application must derive a new class from SoOffscreenVolumeRender and implement :

the boxComputed method. This method is called with parameters that give access to information about the processed box.
the getNextSubBox method. This method must return subBox size smaller than getMaxBoxSize. We recommend to request subbox even smaller in order to get more parallelism between extraction processing (done on GPU) and application processing and reduce peak GPU memory resources used.

The resolution of the extraction is controlled by boxSize field. As extraction is done using GPU techniques, there is a size limit on the boxSize that can be extract in one call. This limit can be retreived through getMaxBoxSize call.

Limitations:

It is not possible to extract a volume displayed as an isosurface (via SoVolumeDataDrawStyle or SoVolumeIsosurface).
SoResetTransform node usage should be avoided in volumeRenderSceneGraph or bboxSceneGraph scene graph, in order to get the best extraction precision even with very flat extraction box. In general it is possible to use SoTransformSeparator node instead.

FILE FORMAT/DEFAULT

SoOffscreenVolumeRender

volumerenderSceneGraph	NULL
bboxSceneGraph	NULL
boxSize	(64, 64, 64)
trigger	FALSE
opacityThreshold	0
components	ALPHA

Member Enumeration Documentation

◆ Components

enum SoOffscreenVolumeRender::Components

Enumerator
ALPHA
RGBA

Definition at line 123 of file SoOffscreenVolumeRender.h.

Constructor & Destructor Documentation

◆ SoOffscreenVolumeRender()

SoOffscreenVolumeRender::SoOffscreenVolumeRender ( )

Default constructor.

Member Function Documentation

◆ getClassTypeId()

static SoType SoOffscreenVolumeRender::getClassTypeId ( )

static

Returns the type identifier for this class.

◆ getMaxBoxSize()

SbVec3i32 SoOffscreenVolumeRender::getMaxBoxSize ( SoState * state = NULL )

Returns the maximum boxSize that can be extract in one boxComputed for the current state.

◆ getTypeId()

virtual SoType SoOffscreenVolumeRender::getTypeId ( ) const

virtual

Returns the type identifier for this specific instance.

Reimplemented from SoNode.

◆ ijkToXyzBox()

SbBox3d SoOffscreenVolumeRender::ijkToXyzBox ( const SbBox3i32 & ijkBox )

Convert ijk box coordinates returned by boxComputed method to the bboxSceneGraph space.

◆ synchronousExtraction()

bool SoOffscreenVolumeRender::synchronousExtraction ( SoSceneManager * sceneManager )

Does extraction synchronously, whereas using trigger field will execute extraction on next redraw.

Parameters

sceneManager the scene manager of the viewer scene to be extracted.

Returns: TRUE on success.

Member Data Documentation

◆ bboxSceneGraph

SoSFNode SoOffscreenVolumeRender::bboxSceneGraph

Head of the scene graph that defines the 3D off-screen scene cube to consider in world coordinates.

Definition at line 107 of file SoOffscreenVolumeRender.h.

◆ boxSize

SoSFVec3i32 SoOffscreenVolumeRender::boxSize

Resolution of the output data in the off-screen box.

Definition at line 110 of file SoOffscreenVolumeRender.h.

◆ components

SoSFEnum SoOffscreenVolumeRender::components

Components to get back from the offscreen render.

Use enum Components. Default is ALPHA.

Definition at line 135 of file SoOffscreenVolumeRender.h.

◆ dataSpaceMatrix

SoSFMatrix SoOffscreenVolumeRender::dataSpaceMatrix

This transformation is applied on the volume render texture coordinate during the extraction.

It allows to change the extraction frame. This matrix is applied on normalized texture coordinates all components are between 0-1 and must be in [0-1] after the transformation. So to inverse an axis, we must apply the following transformation: -1*u+1 (where u is a texture coordinate) and not just a simple negative scale.

To swap I and J axis, the matrix would be:

SbMatrix( 0, 1, 0, 0,
          1, 0, 0, 0,
          0, 0, 1, 0,
          0, 0, 0, 1);

To reverse I axis, the matrix would be:

SbMatrix(-1, 0, 0, 0,
          0, 1, 0, 0,
          0, 0, 1, 0,
          1, 0, 0, 1);

To reverse J axis, the matrix would be:

SbMatrix( 1, 0, 0, 0,
          0,-1, 0, 0,
          0, 0, 1, 0,
          0, 1, 0, 1);

To reverse K axis, the matrix would be:

SbMatrix( 1, 0, 0, 0,
          0, 1, 0, 0,
          0, 0, -1, 0,
          0, 0, 1, 1);

Definition at line 189 of file SoOffscreenVolumeRender.h.

◆ opacityThreshold

SoSFFloat SoOffscreenVolumeRender::opacityThreshold

During extraction, voxels with an opacity less than the specified value will be ignored Default is 0.

Valid range is [0-1].

Definition at line 120 of file SoOffscreenVolumeRender.h.

◆ trigger

SoSFBool SoOffscreenVolumeRender::trigger

Setting this field to TRUE will start the off-screen rendering process.

This field is set to FALSE when computation is finished. Default is FALSE.

Definition at line 115 of file SoOffscreenVolumeRender.h.

◆ volumerenderSceneGraph

SoSFNode SoOffscreenVolumeRender::volumerenderSceneGraph

Head of the scene graph that contains one or multiple VolumeRender node to render in 3D off-screen cube.

Definition at line 104 of file SoOffscreenVolumeRender.h.

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

VolumeViz/nodes/SoOffscreenVolumeRender.h

Open Inventor Release 2023.2.3

Public Types

Public Member Functions

Static Public Member Functions

Public Attributes