Public Member Functions

MPxGeometryData Class Reference

This reference page is linked to from the following overview topics: Geometry data.


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Detailed Description

Base Class for User-defined Dependency Graph Geometry Data Types.

This class is used to provide a wrapper or container for some arbitrary geometry type that you have defined. This allows your data type to exist as typed attributes on dependency nodes and to be passed through dependency graph connections.

MP`xGeometryData is similar to MPxData but includes methods to support sets (also known as groups) and component iteration.

For user defined shapes (MPxSurfaceShape derived classes), in order to support maya's deformers you must declare an MPxGeometryData class as well as a geometry iterator (MPxGeometryIterator).

To register geometry data use MFnPlugin::registerData with the type argument equal to MPxData::kGeometryData.

Examples:

apiMeshData.h.

#include <MPxGeometryData.h>

Inheritance diagram for MPxGeometryData:
Inheritance graph
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List of all members.

Public Member Functions

  MPxGeometryData ()
  Class Constructor.
virtual  ~MPxGeometryData ()
  Class Destructor.
virtual MPxGeometryIterator iterator (MObjectArray &componentList, MObject &component, bool useComponents)
  Associates a control point based geometry iterator with this data.
virtual MPxGeometryIterator iterator (MObjectArray &componentList, MObject &component, bool useComponents, bool world) const
  Associates a control point based geometry iterator with this data.
virtual bool  updateCompleteVertexGroup (MObject &component) const
  This method is used in conjunction with MPxSurfaceShape classes which support maya's deformations.
virtual bool  deleteComponent (const MObjectArray &compList)
  This method should be overridden if this data is to support component deletion.
virtual bool  deleteComponentsFromGroups (const MObjectArray &compList, MIntArray &groupIdArray, MObjectArray &groupComponentArray)
  This method should be overridden to modify the groups that flows along with the geometry, as part of the data, based on the components being deleted.
virtual void  smartCopy (const MPxGeometryData *srcGeom)
  This method is used in conjunction with MPxSurfaceShape classes which support maya's deformations.
virtual void  copy (const MPxData &src)=0
  This method initializes an instance of an MPxGeometryData derived class from another existing instance.
virtual MTypeId  typeId () const =0
  Determines the type id of the Data object.
virtual MString  name () const =0
  Determines the type name of the Data object.
void  setMatrix (const MMatrix &)
  Store the matrix associated to MPxGeometryData.
const MMatrix matrix () const
  Return the matrix associated to MPxGeometryData.
bool  matrix (MMatrix &) const
  Return the matrix associated to MPxGeometryData.

Member Function Documentation

MPxGeometryIterator * iterator ( MObjectArray componentList,
MObject component,
bool  useComponents 
) [virtual]

Associates a control point based geometry iterator with this data.

This method is used in conjunction with MPxSurfaceShape and should be overridden if your shape is to support maya's deformations.

The useComponents argument specifies whether the iteration is over the given componentList or the component.

Parameters:
[in] componentList a list of components that are to be iterated over
[in] component a component to be iterator over
[in] useComponents if true then componentList is to be iterated over, otherwise the iteration is on component.
Returns:
A pointer to an iterator for your geometry
Examples:
apiMeshData.h.
MPxGeometryIterator * iterator ( MObjectArray componentList,
MObject component,
bool  useComponents,
bool  world 
) const [virtual]

Associates a control point based geometry iterator with this data.

This method is used in conjunction with MPxSurfaceShape and should be overridden if your shape is to support maya's deformations.

The useComponents argument specifies whether the iteration is over the given componentList or the component.

This iterator method is called when the iteration is for read only purposes.

Parameters:
[in] componentList a list of components that are to be iterated over
[in] component a component to be iterator over
[in] useComponents if true then componentList is to be iterated over, otherwise the iteration is on component.
[in] world specifies whether the iteration is for world space data
Returns:
A pointer to an iterator for your geometry
bool updateCompleteVertexGroup ( MObject component ) const [virtual]

This method is used in conjunction with MPxSurfaceShape classes which support maya's deformations.

This method should make sure that complete vertex group data is up-to-date. If the given component is not complete (i.e. it represents all elements of your geometry) then you must mark is as complete using the methods of MFnComponent and return true if the component was updated, false if it was already complete.

This method is used by deformers when deforming the "whole" object and not just selected components.

Parameters:
[in] component the component to test
Returns:
Returns true if the component was updated, false if it was already complete
Examples:
apiMeshData.h.
bool deleteComponent ( const MObjectArray compList ) [virtual]

This method should be overridden if this data is to support component deletion.

For user defined shapes (MPxSurfaceShape) which support components, this method must be overridden if component deletion is to be supported when the shape has history.

Parameters:
[in] compList a list of components that are to be deleted
Returns:
true if the deletion was successfull, false otherwise
bool deleteComponentsFromGroups ( const MObjectArray compList,
MIntArray groupIdArray,
MObjectArray groupComponentArray 
) [virtual]

This method should be overridden to modify the groups that flows along with the geometry, as part of the data, based on the components being deleted.

It should intelligently update the groups based on what gets deleted. The class MFnGeometryData can be used to access and modify grouping information for data.

The groupIdArray and groupComponentArray should contain the updated grouping information after the deletion has occurred.

Parameters:
[in] compList a list of components that are to be deleted
[in] groupIdArray array of group id's
[in] groupComponentArray array of updated components, one for each group id
Returns:
true if the deletion was successfull, false otherwise
void smartCopy ( const MPxGeometryData srcGeom ) [virtual]

This method is used in conjunction with MPxSurfaceShape classes which support maya's deformations.

This method is used to prvoide maya with an efficient way to copy the source data into the memory of this data with as little memory allocation as possible.

This method is not mandatory and only needs to be overridden to improve performance of deformations on shapes.

Parameters:
[in] srcGeom a pointer to the data to be copied
void copy ( const MPxData src ) [pure virtual]

This method initializes an instance of an MPxGeometryData derived class from another existing instance.

This method can be thought of as the second half of a copy constructor for the class. The default constructor has already been called for the instance, and this method is used to set the private data by copying the values from an existing instance. This is a pure virtual method, and must be overridden in derived classes.

Parameters:
[in] src The object from which to copy the private data

Implements MPxData.

Examples:
apiMeshData.h.
MTypeId typeId ( ) const [pure virtual]

Determines the type id of the Data object.

This is a pure virtual method, and must be overridden in derived classes.

Returns:
Type id of the Data object

Implements MPxData.

Examples:
apiMeshData.h.
MString name ( ) const [pure virtual]

Determines the type name of the Data object.

This is a pure virtual method, and must be overridden in derived classes.

Returns:
Type name of the Data object

Implements MPxData.

Examples:
apiMeshData.h.
void setMatrix ( const MMatrix m )

Store the matrix associated to MPxGeometryData.

The matrix transformation will take place when the data is used, for example in deformer.

Parameters:
[in] m the matrix to transfer a point from local object space to world space.
const MMatrix & matrix ( ) const

Return the matrix associated to MPxGeometryData.

Returns:
MMatrix that takes a point from local object space to world space
bool matrix ( MMatrix m ) const

Return the matrix associated to MPxGeometryData.

Parameters:
[out] m the returned matrix that takes a point from local object space to world space.
Returns:
true if m is not an identity matrix, false otherwise

MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData
MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData MPxGeometryData