python/api2/py2ConvertVerticesToFacesCmd.py

#-
# ==========================================================================
# Copyright 2015 Autodesk, Inc.  All rights reserved.
#
# Use of this software is subject to the terms of the Autodesk
# license agreement provided at the time of installation or download,
# or which otherwise accompanies this software in either electronic
# or hard copy form.
# ==========================================================================
#+

from builtins import next
import sys
import maya.cmds as cmds
import maya.api.OpenMaya as om

def maya_useNewAPI():
    """
    The presence of this function tells Maya that the plugin produces, and
    expects to be passed, objects created using the Maya Python API 2.0.
    """
    pass

##############################################################################
##
## Command class implementation
##
##############################################################################
class convertVerticesToFacesCmd(om.MPxCommand):
    s_name = "py2ConvertVerticesToFaces"
    
    def __init__(self):
        om.MPxCommand.__init__(self)
        self.previousSelectionList = None

    @staticmethod
    def creator():
        return convertVerticesToFacesCmd()

    def doIt(self, args):
        self.previousSelectionList = om.MGlobal.getActiveSelectionList()
        self.redoIt()

    def redoIt(self):
        multiVertexComponent = None
        singleVertexComponent = None
        finalFacesSelection = om.MSelectionList()
        vertexComponentIter = om.MItSelectionList(self.previousSelectionList, om.MFn.kMeshVertComponent)
        while not vertexComponentIter.isDone():
            meshDagPath, multiVertexComponent = vertexComponentIter.getComponent()
            meshName = meshDagPath.fullPathName();
            if multiVertexComponent is not None:
                itMeshVertex = om.MItMeshVertex(meshDagPath, multiVertexComponent)
                connectedFacesIndices = itMeshVertex.getConnectedFaces()
                faceIter = om.MItMeshPolygon(meshDagPath)

                for i in connectedFacesIndices :
                    #GET THE VERTEX INDICES FOR CURRENT FACE:
                    faceIter.setIndex(i);
                    faceVerticesIndices = faceIter.getVertices()
                    faceIsContained = True
                    for j in faceVerticesIndices :
                        singleVertexList = om.MSelectionList() 
                        singleVertexList.clear()
                        vertexName = meshName 
                        vertexName += ".vtx["
                        vertexName += str(j)
                        vertexName += "]"
                        singleVertexList.add(vertexName)
                        meshDagPath, singleVertexComponent = singleVertexList.getComponent(0)
                        ##SEE WHETHER VERTEX BELONGS TO ORIGINAL SELECTION, AND IF IT DOESN'T, THEN THE WHOLE FACE IS NOT CONTAINED:
                        if not self.previousSelectionList.hasItem((meshDagPath, singleVertexComponent)):
                            faceIsContained = False
                            break
                    ##IF FACE IS "CONTAINED", ADD IT TO THE FINAL CONTAINED FACES LIST:
                    if faceIsContained:
                        faceName = meshName 
                        faceName += ".f["
                        faceName += str(i)
                        faceName += "]"
                        finalFacesSelection.add(faceName)
            next(vertexComponentIter)


        ## FINALLY, MAKE THE NEW "CONTAINED FACES", THE CURRENT SELECTION:
        om.MGlobal.setActiveSelectionList(finalFacesSelection, om.MGlobal.kReplaceList)
        ## RETURN NEW CONTAINED FACES LIST FROM THE MEL COMMAND, AS AN ARRAY OF STRINGS:
        containedFacesArray = finalFacesSelection.getSelectionStrings()
        om.MPxCommand.setResult(containedFacesArray)
    
    def isUndoable(self):
        return True

    def undoIt(self):
        om.MGlobal.setActiveSelectionList(self.previousSelectionList, om.MGlobal.kReplaceList)

##############################################################################
##
## The following routines are used to register/unregister
## the command we are creating within Maya
##
##############################################################################
def initializePlugin(obj):
    plugin = om.MFnPlugin(obj, "Autodesk", "4.0", "Any")
    try:
        plugin.registerCommand(convertVerticesToFacesCmd.s_name, convertVerticesToFacesCmd.creator)
    except:
        sys.stderr.write("Failed to register command\n")
        raise

def uninitializePlugin(obj):
    plugin = om.MFnPlugin(obj)
    try:
        plugin.deregisterCommand(convertVerticesToFacesCmd.s_name)
    except:
        sys.stderr.write("Failed to deregister command\n")
        raise