Public Member Functions | Static Public Member Functions

MItGeometry Class Reference

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Detailed Description

Iterator class for geometry data.

This class is the iterator class for geometry data, and can be used to loop over the CVs of NURBS, the points of subds & lattices, and the vertices of polygonal meshes.

Examples:
Simple traversal.
    MItGeometry iter( dagPath );
    for ( ; !iter.isDone(); iter.next() )
    {
        MPoint pt = iter.position();

        // do something with it
    }

Traversal of a geometry group within a compute() method.

    MStatus
    exampleIterator::compute(const MPlug& plug, MDataBlock& dataBlock)
    {
        MStatus status;

        if (plug.attribute() == oOutputGeometry) {
            // get the input geometry and input groupId
            MDataHandle hInputGeom = dataBlock.inputValue(inputGeomAttr);
            MDataHandle hGroupId = dataBlock.inputValue(inputGroupIdAttr);

            unsigned int groupId = hGroup.asLong();
            MDataHandle hOutput = dataBlock.outputValue(plug);
            hOutput.copy(hInputGeom);

            // do an iteration where we get each point and set it to a new value
            MItGeometry iter(hOutput,groupId,false);
            for ( ; !iter.isDone(); iter.next()) {
                MPoint pt = iter.position();

                // do something here to modify the point ...

                iter.setPosition(pt);
            }
        } else {
            status = MStatus::kUnknownParameter;
        }        

        return status;
    }
Examples:

clusterWeightFunction.cpp, exportJointClusterDataCmd.cpp, exportSkinClusterDataCmd.cpp, offsetNode.cpp, and yTwistNode.cpp.

#include <MItGeometry.h>

List of all members.

Public Member Functions

 MItGeometry (const MDagPath &dagPath, MStatus *ReturnStatus=NULL)
 Constructor.
 MItGeometry (const MDagPath &dagPath, MObject &component, MStatus *ReturnStatus=NULL)
 Constructor.
 MItGeometry (MObject &dagObject, MStatus *ReturnStatus=NULL)
 Constructor.
 MItGeometry (MDataHandle &dataHandle, unsigned int groupId, bool readOnly=true, MStatus *ReturnStatus=NULL)
 Constructor.
 MItGeometry (MDataHandle &dataHandle, bool readOnly=true, MStatus *ReturnStatus=NULL)
 Constructor.
virtual ~MItGeometry ()
 Class destructor.
bool isDone (MStatus *ReturnStatus=NULL) const
 Returns true if the iteration is finished, i.e.
MStatus next ()
 Advance to the next component in the iteration.
MPoint position (MSpace::Space space=MSpace::kObject, MStatus *ReturnStatus=NULL) const
 Return the position of the current point/CV/vertex component.
MStatus setPosition (const MPoint &point, MSpace::Space space=MSpace::kObject)
 Set the position of the current point/CV/vertex.
MWeight weight (MStatus *ReturnStatus=NULL) const
 Return the weight of the current point/CV/vertex component.
int index (MStatus *ReturnStatus=NULL) const
 This method returns the index of the current point/CV/vertex component in the iteration.
MObject component (MStatus *ReturnStatus=NULL) const
 This method is obsolete.
MObject currentItem (MStatus *ReturnStatus=NULL) const
 This method returns the current component in the iteration.
int count (MStatus *ReturnStatus=NULL) const
 Return the number of items in this iteration.
int exactCount (MStatus *ReturnStatus=NULL)
 Return the exact number of items in this iteration.
MStatus reset ()
 Reset the iterator to the first component.
MStatus allPositions (MPointArray &points, MSpace::Space space=MSpace::kObject) const
 Return the position of all the points/CVs/vertices.
MStatus setAllPositions (const MPointArray &points, MSpace::Space space=MSpace::kObject)
 Set the position of all the points/CVs/vertices at once.

Static Public Member Functions

static const char * className ()
 Returns the name of this class.

Constructor & Destructor Documentation

MItGeometry ( const MDagPath dagPath,
MStatus ReturnStatus = NULL 
)

Constructor.

This constructor is used to iterate over all of the points/CV/vertices of a dag object given a particular dag path.

Parameters:
[in]dagPathThe dag path to the object.
[out]ReturnStatusStatus code
Status Codes:
MItGeometry ( const MDagPath dagPath,
MObject component,
MStatus ReturnStatus = NULL 
)

Constructor.

This constructor is used to iterate over the points/CVs/vertices of a dag object given a particular dag path. The iteration will be over the points/CVs/Vertices specified by the component argument. If the component is null then the iteration will be over the entire object.

Parameters:
[in]dagPathThe dag path to the object.
[in]componentThe components of the object to iterate over. If this is null then the iteration will be over all components of the object.
[out]ReturnStatusStatus code
Status Codes:
MItGeometry ( MObject dagObject,
MStatus ReturnStatus = NULL 
)

Constructor.

This constructor is used to iterate over all of the points/CV/vertices of the given dag object. Since there is no path information passed into this constructor world space operations will not be possible.

Parameters:
[in]dagObjectThe DAG object to iterate.
[out]ReturnStatusStatus code
Status Codes:
MItGeometry ( MDataHandle dataHandle,
unsigned int  groupId,
bool  readOnly = true,
MStatus ReturnStatus = NULL 
)

Constructor.

This constructor is used when iterating from within the compute() method of a node. The point/CV/vertex components of the specified group within the geometry data that is pointed to by the dataHandle will be iterated. If readOnly mode is set to false, the setPosition method can be utilized.

Parameters:
[in]dataHandleThe dataHandle pointing to the geometry data.
[in]groupIdThe id of the group whose components will be iterated.
[in]readOnlyIf false you will be allowed to modify the geometry position data during the iteration.
[out]ReturnStatusStatus code
Status Codes:
MItGeometry ( MDataHandle dataHandle,
bool  readOnly = true,
MStatus ReturnStatus = NULL 
)

Constructor.

This constructor is used when iterating from within the compute() method of a node. The point/CV/vertex components of the geometry data pointed to by the dataHandle will be iterated. If readOnly mode is set to false, the setPosition method can be utilized.

Parameters:
[in]dataHandleThe dataHandle pointing to the geometry data.
[in]readOnlyIf false you will be allowed to modify the geometry position data during the iteration.
[out]ReturnStatusStatus code
Status Codes:
~MItGeometry ( ) [virtual]

Class destructor.

Deallocates memory used by this iterator.


Member Function Documentation

bool isDone ( MStatus ReturnStatus = NULL) const

Returns true if the iteration is finished, i.e.

there are no more components to iterate on.

Parameters:
[out]ReturnStatusStatus code
Returns:
Bool true if There are no more components to iterate on, false otherwise.
Status Codes:
Examples:
offsetNode.cpp, and yTwistNode.cpp.
MStatus next ( )

Advance to the next component in the iteration.

If the iterator is already at the last component then this method has no effect. Use isDone to determine if the iterator is at the last component.

Returns:
Status code
Status Codes:
Examples:
offsetNode.cpp, and yTwistNode.cpp.
MPoint position ( MSpace::Space  space = MSpace::kObject,
MStatus ReturnStatus = NULL 
) const

Return the position of the current point/CV/vertex component.

Parameters:
[in]spaceThe transformation space in which the operation is done
[out]ReturnStatusStatus code
Returns:
Status code
Status Codes:
Examples:
offsetNode.cpp, and yTwistNode.cpp.
MStatus setPosition ( const MPoint pt,
MSpace::Space  space = MSpace::kObject 
)

Set the position of the current point/CV/vertex.

Parameters:
[in]ptNew position.
[in]spaceThe transformation space in which the operation is done.
Returns:
Status code
Status Codes:
Examples:
offsetNode.cpp, and yTwistNode.cpp.
MWeight weight ( MStatus ReturnStatus = NULL) const

Return the weight of the current point/CV/vertex component.

Parameters:
[out]ReturnStatusStatus code
Returns:
The current component's weight
int index ( MStatus ReturnStatus = NULL) const

This method returns the index of the current point/CV/vertex component in the iteration.

Parameters:
[out]ReturnStatusStatus code
Returns:
The index of the current point/CV/vertex.
Status Codes:
Examples:
offsetNode.cpp.
MObject component ( MStatus ReturnStatus = NULL) const

This method is obsolete.

Deprecated:
Use the method MItGeometry::currentItem instead.

This method returns the current component in the iteration.

Parameters:
[out]ReturnStatusStatus code
Returns:
The current component in the iteration.
Status Codes:
MObject currentItem ( MStatus ReturnStatus = NULL) const

This method returns the current component in the iteration.

Parameters:
[out]ReturnStatusStatus code
Returns:
The current component in the iteration.
Status Codes:
int count ( MStatus ReturnStatus = NULL) const

Return the number of items in this iteration.

This number will always be at least as large as the number of items, however in some cases it may be larger. It is useful if allocating space in an array to hold the results, since it will always be of sufficient size. If the exact number of items is required, use the exactCount method instead. The exactCount method is however significantly slower than this method.

Parameters:
[out]ReturnStatusStatus code
Returns:
The number of items that will be iterated
Status Codes:
int exactCount ( MStatus ReturnStatus = NULL)

Return the exact number of items in this iteration.

This method is significantly slower than the count() method, so use if only if the precise number is required.

Parameters:
[out]ReturnStatusStatus code
Returns:
The number of items that will be iterated
Status Codes:
MStatus reset ( )

Reset the iterator to the first component.

Returns:
Status code
Status Codes:
MStatus allPositions ( MPointArray points,
MSpace::Space  space = MSpace::kObject 
) const

Return the position of all the points/CVs/vertices.

This operation is faster than using the iterator to get values one by one, but uses more memory as it requires an array to hold all the values to be returned.

Parameters:
[out]pointsStorage for positions
[in]spaceThe transformation space in which the operation is done
Returns:
Status code
Status Codes:
MStatus setAllPositions ( const MPointArray pt,
MSpace::Space  space = MSpace::kObject 
)

Set the position of all the points/CVs/vertices at once.

This operation is faster than using the iterator to set values one by one, but uses more memory as it requires an array to hold all the values to be set.

Parameters:
[in]ptAn array containing all the positions to be set
[in]spaceThe transformation space in which the operation is done
Returns:
Status code
Status Codes:
const char * className ( ) [static]

Returns the name of this class.

Returns:
The name of this class.

MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry
MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry MItGeometry