Public Types | Public Member Functions

MPxPolyTrg Class Reference

This reference page is linked to from the following overview topics: Overview of example plug-ins, Example C++ plug-in descriptions.


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Detailed Description

User defined poly triangulation support.

MPxPolyTrg is the the parent class for nodes which define a custom face triangulation for meshes. In order to override default maya triangulation, the user has to do the following things:

Once the node is defined, the user has to inform the mesh about it. For each mesh the user wants to override the default triangulation, he has to set the usertTrg attribute on the mesh to the name under which the function has been registered.

Example: /code setAttr mesh.userTrg -type "string" "triangulate"; /endcode

Once that attribute is set, the default maya triangulation is turned off and the one provided by the user is used to draw the mesh.

Examples:

polyTrgNode.cpp.

#include <MPxPolyTrg.h>

Inheritance diagram for MPxPolyTrg:
Inheritance graph
[legend]

List of all members.

Public Types

typedef void(* polyTrgFnct )(const float *vert, const float *norm, const int *loopSizes, const int nbLoop, const int nbTrg, unsigned short *trg)
 Pointer to a function which triangulates a poly face.

Public Member Functions

 MPxPolyTrg ()
 Constructor.
virtual ~MPxPolyTrg ()
 Destructor.
virtual void postConstructor ()
 Post constructor.
virtual MStatus compute (const MPlug &plug, MDataBlock &dataBlock)
 This method should be overridden in user defined nodes.
virtual bool isAbstractClass () const
 Each new node has to implement that fuction.
MStatus registerTrgFunction (char *name, polyTrgFnct f)
 Register a triangulation function with maya.
MStatus unregisterTrgFunction (char *name)

Constructor & Destructor Documentation

Constructor.

The constructor should never call any methods from MPxPolyTrg or make any calls that require the existence of the MObject associated with the user defined node. The postConstructor method should be used to do any initialization of this kind.


Member Function Documentation

void postConstructor ( ) [virtual]

Post constructor.

Internally maya creates two objects when a user defined node is created, the internal MObject and the user derived object. The association between the these two objects is not made until after the MPxPolyTrg constructor is called. This implies that no MPxPolyTrg member function can be called from the MPxPolyTrg constructor. The postConstructor will get called immediately after the constructor when it is safe to call any MPxPolyTrg member function.

Reimplemented from MPxNode.

Examples:
polyTrgNode.cpp.
MStatus compute ( const MPlug plug,
MDataBlock block 
) [virtual]

This method should be overridden in user defined nodes.

However, fror this particaular node we don't need to to do anything in the compute functione. Therefore, all we do is return MS:kSuccess in the derive class.

Parameters:
[in]plugplug representing the attribute that needs to be recomputed
[in]blockdata block containing storage for the node's attributes
Returns:
Status code
Status Codes:

Reimplemented from MPxNode.

Examples:
polyTrgNode.cpp.
bool isAbstractClass ( ) const [virtual]

Each new node has to implement that fuction.

It returns false since this is not an abstract class.

Returns:
False

Reimplemented from MPxNode.

Examples:
polyTrgNode.cpp.
MStatus registerTrgFunction ( char *  functName,
polyTrgFnct  funct 
)

Register a triangulation function with maya.

The name provided as a first argument is the name under which the function is registered. This name has to be used when setting 'userTrg' attribute on a mesh.

Parameters:
[in]functNameFunction name under which the function is register with maya.
[in]functPointer to the static function which implement a face triangulation.
Returns:
Status code
Status Codes:
MStatus unregisterTrgFunction ( char *  functName)
Parameters:
[in]functNameFunction name under which the function is register with maya.
Returns:
Status code
Status Codes:

MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg
MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg MPxPolyTrg