plug-in to manage mesh invisible faces

invisibleFacesMixer.py

'''
import maya.cmds as cmds
cmds.loadPlugin("/path/to/invisibleFacesMixer.py", quiet=True)

cmds.file(new=True, f=True)
cmds.flushUndo()
cmds.unloadPlugin("invisibleFacesMixer.py")
cmds.loadPlugin("/path/to/invisibleFacesMixer.py")

#lastFile = cmds.optionVar(q='RecentFilesList')[-1]; cmds.file(lastFile, o=True, f=True)

clm = cmds.createNode('invisibleFacesMixer')
f1 = ' '.join([str(i) for i in range(80 ,100)])
f2 = ' '.join([str(i) for i in range(120,140)])
f3 = ' '.join([str(i) for i in range(160,180)])
cmds.setAttr('%s.invisibleFacesData[0].faceIds' %clm, f1, type='string')
cmds.setAttr('%s.invisibleFacesData[1].faceIds' %clm, f2, type='string')
cmds.setAttr('%s.invisibleFacesData[2].faceIds' %clm, f3, type='string')
meshGenerator = cmds.createNode('polyTorus')
mesh1 = cmds.createNode('mesh')
mesh2 = cmds.createNode('mesh')
cmds.move(5, 0, 0, r=True)
cmds.connectAttr('%s.output'%meshGenerator, '%s.inMesh' %mesh1)
cmds.connectAttr('%s.outMesh' %mesh1, '%s.inMesh' %clm)
cmds.connectAttr('%s.outMesh' %clm, '%s.inMesh' %mesh2)
cmds.setAttr('%s.displayInvisibleFaces' %mesh2, 1)
cmds.sets([mesh1, mesh2], e=True, forceElement='initialShadingGroup')
cmds.select(clm, r=True)
cmds.delete(mesh1,ch=True)

# As of now, if you play with the various invisibleFacesMixer1 hide attributes, works ok

# But if you perform this operation, it breaks the node behavior
cmds.select('%s.f[115]' %mesh1, r=True)
cmds.polyHole(assignHole=True)
'''

import sys

import maya.OpenMaya as OpenMaya
import maya.OpenMayaMPx as OpenMayaMPx

kPluginNodeTypeName = "invisibleFacesMixer"  # type du node
kPluginNodeTypeId   = OpenMaya.MTypeId(0x8705)


class InvisibleFacesMixer(OpenMayaMPx.MPxNode):  # Premiere lette Majuscule
    # class variables
    # Ici on fait des MObject() representant les attributs du node
    inMesh        = OpenMaya.MObject()
    outMesh       = OpenMaya.MObject()
    compListData  = OpenMaya.MObject()
    compList      = OpenMaya.MObject()
    showHide      = OpenMaya.MObject()

    def __init__(self):
        OpenMayaMPx.MPxNode.__init__(self)

    def compute(self, plug, data):
        if not plug == self.outMesh:
            return OpenMaya.kUnknownParameter

        hInMesh  = data.inputValue(self.inMesh)
        oInMesh  = hInMesh.data()
        hOutMesh = data.outputValue(InvisibleFacesMixer.outMesh)

        dataCreator   = OpenMaya.MFnMeshData()
        newOutputData = dataCreator.create()
        fnOutMesh     = OpenMaya.MFnMesh()
        fnOutMesh.copy(oInMesh, newOutputData)

        fnInMesh   = OpenMaya.MFnMesh(oInMesh)
        invFacesIn = fnInMesh.getInvisibleFaces()
        print 'invFaces before clean:', invFacesIn

        # If I perform the following block, the node 
        # fails to produce correct results if there is any 
        # invisibleFaces on the source mesh

        # Culprit code start
        # Cleaning incoming invisibleFaces
        a = OpenMaya.MUintArray()
        for i in invFacesIn:
            a.append(i)
        fnOutMesh.setInvisibleFaces(a, True)
        invFacesOut = fnOutMesh.getInvisibleFaces()
        print 'invFaces after clean:', invFacesOut
        # Culprit code end

        arrayHandle = data.inputArrayValue(self.compListData)
        count = arrayHandle.elementCount()

        idsSet = set()

        for i in xrange(count):
            arrayHandle.jumpToArrayElement(i)
            hshowHide   = arrayHandle.inputValue().child(self.showHide)
            hCompIds = arrayHandle.inputValue().child(self.compList)

            showHideVal = hshowHide.asBool()
            compIds     = hCompIds.asString()

            if not showHideVal or not compIds:
                continue

            for compId in compIds.split(' '):
                idsSet.add(int(compId))

        b = OpenMaya.MUintArray()

        for compId in idsSet:
            b.append(compId)
        print 'invFaces to install:', b
        fnOutMesh.setInvisibleFaces(b, False)

        invFacesOut2 = fnOutMesh.getInvisibleFaces()
        print 'invFaces final:', invFacesOut2
        hOutMesh.setMObject(newOutputData)

        data.setClean(plug)


def nodeInitializer():

    nAttrInMesh = OpenMaya.MFnTypedAttribute()
    InvisibleFacesMixer.inMesh = nAttrInMesh.create('inMesh', 'i', OpenMaya.MFnData.kMesh)
    # nAttrInMesh.setStorable(True)
    nAttrInMesh.setConnectable(True)

    nAttrOutMesh = OpenMaya.MFnTypedAttribute()
    InvisibleFacesMixer.outMesh = nAttrOutMesh.create('outMesh', 'o', OpenMaya.MFnData.kMesh)
    nAttrOutMesh.setConnectable(True)
    # nAttrOutMesh.setStorable(True)

    # compListData attribute
    cAttrCompListData = OpenMaya.MFnCompoundAttribute()
    InvisibleFacesMixer.compListData = cAttrCompListData.create('invisibleFacesData', 'ifd')
    cAttrCompListData.setStorable(True)
    cAttrCompListData.setArray(True)

    nAttrshowHide = OpenMaya.MFnNumericAttribute()
    InvisibleFacesMixer.showHide = nAttrshowHide.create('hide', 'h', OpenMaya.MFnNumericData.kBoolean, 0)
    nAttrshowHide.setStorable(True)
    nAttrshowHide.setKeyable(True)

    nAttrCompList = OpenMaya.MFnTypedAttribute()
    InvisibleFacesMixer.compList = nAttrCompList.create('faceIds', 'fids', OpenMaya.MFnData.kString)
    nAttrCompList.setStorable(True)

    # Add child attributes to compound
    cAttrCompListData.addChild(InvisibleFacesMixer.showHide)
    cAttrCompListData.addChild(InvisibleFacesMixer.compList)

    # add attributes
    InvisibleFacesMixer.addAttribute(InvisibleFacesMixer.inMesh)
    InvisibleFacesMixer.addAttribute(InvisibleFacesMixer.outMesh)
    InvisibleFacesMixer.addAttribute(InvisibleFacesMixer.compListData)

    # affects
    InvisibleFacesMixer.attributeAffects(InvisibleFacesMixer.inMesh, InvisibleFacesMixer.outMesh)
    InvisibleFacesMixer.attributeAffects(InvisibleFacesMixer.showHide, InvisibleFacesMixer.outMesh)
    InvisibleFacesMixer.attributeAffects(InvisibleFacesMixer.compList, InvisibleFacesMixer.outMesh)
    InvisibleFacesMixer.attributeAffects(InvisibleFacesMixer.compListData, InvisibleFacesMixer.outMesh)


def nodeCreator():
    return OpenMayaMPx.asMPxPtr(InvisibleFacesMixer())


def initializePlugin(mobject):
    mplugin = OpenMayaMPx.MFnPlugin(mobject, "Nicolas Combecave", "1.0", "Any")
    try:
        mplugin.registerNode(kPluginNodeTypeName, kPluginNodeTypeId, nodeCreator, nodeInitializer)
    except:
        sys.stderr.write("Failed to register node: %s\n" % kPluginNodeTypeName)
        raise


def uninitializePlugin(mobject):
    mplugin = OpenMayaMPx.MFnPlugin(mobject)
    try:
        mplugin.deregisterNode(kPluginNodeTypeId)
    except:
        sys.stderr.write("Failed to unregister node: %s\n" % kPluginNodeTypeName)
        raise