Open Inventor Release 2023.2.3
 
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SoCSGShape Class Reference

VSG extension Shape defined by a binary boolean operation on two sub scene graphs. More...

#include <Inventor/nodes/SoCSGShape.h>

+ Inheritance diagram for SoCSGShape:

Public Types

enum  CsgOperationType {
  ADD ,
  SUB ,
  INTERSECTION ,
  LEFT_ONLY ,
  RIGHT_ONLY ,
  NOTHING ,
  ALL
}
 CSG operation to be used. More...
 
enum  CsgStatus {
  CSG_NO_ERROR ,
  CSG_LIB_NOT_AVAILABLE ,
  CSG_ERROR
}
 Status of CSG operation. More...
 
- Public Types inherited from SoShape
enum  ShapeType {
  POINTS ,
  LINES ,
  POLYGONS ,
  TEXT
}
 Basic type for antialiased rendering for this shape (Do not consider the SoDrawStyle property currently in the state). More...
 

Public Member Functions

virtual SoType getTypeId () const
 Returns the type identifier for this specific instance.
 
 SoCSGShape ()
 Constructor.
 
void setMaxAttempt (int maxAttempt)
 If the CSG Operation failed for any reason, it will be retried by applying a small random transformation to the operand vertices.
 
CsgStatus getStatus ()
 Returns status of csg operation.
 
- Public Member Functions inherited from SoShape
virtual SbBool affectsState () const
 Overrides default method on SoNode.
 
ShapeType getShapeType ()
 Gets the current shape Full Scene Antialiasing type.
 
- 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 SoNodecopy (SbBool copyConnections=FALSE) const
 Creates and returns an exact copy of the node.
 
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 SoFieldgetField (const SbName &fieldName) const
 Returns a the field of this object whose name is fieldName.
 
virtual SoFieldgetEventIn (const SbName &fieldName) const
 Returns a the eventIn with the given name.
 
virtual SoFieldgetEventOut (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 void setRescueOperation (CsgOperationType op)
 Set operation to use if the CSG operation fails or CSGLib is not available.
 
- Static Public Member Functions inherited from SoShape
static SoType getClassTypeId ()
 Returns the type identifier for this class.
 
static SbBool isPrimitiveRestartAvailable (SoState *state=NULL)
 Returns TRUE if the primitive restart feature is available.
 
- Static Public Member Functions inherited from SoNode
static SoType getClassTypeId ()
 Returns the type identifier for this class.
 
static SoNodegetByName (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 leftOperand
 Geometry scene graph to be used as left operand for the Boolean operation.
 
SoSFNode rightOperand
 Geometry scene graph to be used as right operand for the Boolean operation.
 
SoSFEnum csgOperation
 CSG boolean operation to apply.
 
- Public Attributes inherited from SoShape
SoSFBool boundingBoxIgnoring
 Whether to ignore this node during bounding box traversal.
 

Detailed Description

VSG extension Shape defined by a binary boolean operation on two sub scene graphs.

This shape represents the result of a Constructive Solid Geometry (CSG) operation applied on the two scene graphs leftOperand and rightOperand. Constructive solid geometry allows the application to create a (potentially) complex object by using Boolean operators to combine (relatively) simple objects.

The left and right operands can be any scene graph, including other SoCSGShape nodes. You can define a complex CSG geometry by creating a tree using multiple SoCSGShape nodes. The specified scene graph's shapes must be closed (no holes) and CCW-orientated (all triangles composing shapes must be counter-clockwise).

Each time an operand is modified, a CSG Operation is performed. Keep this in mind if you create a CSGTree (SoCSGShape which contains other SoCSGShapes), especially if you use associative and commutative operations (only additions or only intersections) because the result of such operations does not depend on the tree ( (A + B) + C = A + (B + C) ). In this case, try to build your tree by putting the most often modified nodes at the top of the tree.

For example, a tree optimized for modification on first node ( N1 ) will look like this:

    S
  __|__S
 |   __|__S
N1  |   __|__S
   N2  |   __|__
      N3  |     |
         N4    N5

Where S are SoCSGShape and N1, N2, ... are ordinary nodes. In this case, a modification on N1 will need only 1 csgOperation, whereas a modificaion on N5 will need 4 csgOperations to regenerate the resulting shape.

A tree optimized for random modification will try to minimize its depth:

                  S
          ________|_________
         |                  |
     ____S____          ____S____
    |         |        |         |
  __S__       N3       N4        N5
 |     |
 N1    N2

In this case, any modification will require at most 3 CSG Operations.

NOTE: node available since Open Inventor 8.6

FILE FORMAT/DEFAULT

    CSGShape {
    leftOperand NULL
    rightOperand NULL
    csgOperation ADD
    }

NOTES

    • CSG means Constructive Solid Geometry.
    • Some operations are not commutative (A - B) != (B - A).

    LIMITATIONS Only vertices are handled in the generated shape. None of the normal, color, or texCoord properties of the left or right operands are taken into account. Shaders are also not taken in account, even vertex shaders. But note that you can use a shader above SoCSGShape. The shader will be applied to the result of the CSG operation.

SEE ALSO

SoShape

Definition at line 129 of file SoCSGShape.h.

Member Enumeration Documentation

◆ CsgOperationType

CSG operation to be used.

Enumerator
ADD 

leftOperand union rightOperand.

Remove useless faces and create edges if necessary.

SUB 

LeftOperand - rightOperand.

Remove useless faces and create edges if necessary.

INTERSECTION 

LeftOperand intersect rightOperand.

Remove useless faces and create edges if necessary.

LEFT_ONLY 

Keep only leftOperand.

RIGHT_ONLY 

Keep only rightOperand.

NOTHING 

Keep nothing (result will be empty).

May be useful for debugging.

ALL 

Keep left and right primitives (concatenate all resulting faces).

May be useful for debugging.

Definition at line 139 of file SoCSGShape.h.

◆ CsgStatus

Status of CSG operation.

Status can be queried using the getStatus() method.

Enumerator
CSG_NO_ERROR 

No error.

CSG_LIB_NOT_AVAILABLE 

CSGLib is not available.

CSG_ERROR 

an error occurred

Definition at line 172 of file SoCSGShape.h.

Constructor & Destructor Documentation

◆ SoCSGShape()

SoCSGShape::SoCSGShape ( )

Constructor.

Member Function Documentation

◆ getClassTypeId()

static SoType SoCSGShape::getClassTypeId ( )
static

Returns the type identifier for this class.


◆ getStatus()

CsgStatus SoCSGShape::getStatus ( )

Returns status of csg operation.

Note
Status is updated only when the node is traversed. Initially returns CSG_NO_ERROR. Use enum CsgStatus.

◆ getTypeId()

virtual SoType SoCSGShape::getTypeId ( ) const
virtual

Returns the type identifier for this specific instance.

Reimplemented from SoShape.

◆ setMaxAttempt()

void SoCSGShape::setMaxAttempt ( int  maxAttempt)

If the CSG Operation failed for any reason, it will be retried by applying a small random transformation to the operand vertices.

This can solve the problem if the geometries are well formed, but for example 2 faces are coplanar. This method sets the max number of times SoCSGShape will retry before giving up and using the rescueOperation (see setRescueOperation). A max attempt of 5 is enough. If CSG Operation fails after 5 attempts, it will probably fail all the time.

Default is 5.

Warning
A value > 0 may change the coordinates of geometries as they will be transformed a little bit to apply the CSG operation. This transformation is normally not visible to the naked eye (it's about 0.01%), but may cause issues if you need precise values.

◆ setRescueOperation()

static void SoCSGShape::setRescueOperation ( CsgOperationType  op)
static

Set operation to use if the CSG operation fails or CSGLib is not available.

Default is NOTHING. Must be one of LEFT_ONLY, RIGHT_ONLY, NOTHING or ALL. Use enum CsgOperationType.

Member Data Documentation

◆ csgOperation

SoSFEnum SoCSGShape::csgOperation

CSG boolean operation to apply.

Use enum CsgOperationType. Default is ADD.

Definition at line 166 of file SoCSGShape.h.

◆ leftOperand

SoSFNode SoCSGShape::leftOperand

Geometry scene graph to be used as left operand for the Boolean operation.

Definition at line 158 of file SoCSGShape.h.

◆ rightOperand

SoSFNode SoCSGShape::rightOperand

Geometry scene graph to be used as right operand for the Boolean operation.

Definition at line 161 of file SoCSGShape.h.


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