Deform function not called when editing deformer membership in Maya 2018

[Angelo]

I noticed the deform function doesn't call when you edit the deformer membership of a custom deformer in Maya 2018 but it does in 2016. Is there something new that has to be done?

you can test it with Chad Vernon's python implementation of the blendNode (http://www.chadvernon.com/blog/resources/maya-api-programming/deformers/)

I adjusted the code so that it works with the newer versions of Maya. Removing points from the deformer membership in this plugin works as expected in 2016 but not in 2018.

# ------------------------------------------------------------------------------------------- #

import maya.OpenMayaMPx as OpenMayaMPx

import maya.OpenMaya as OpenMaya

import maya.cmds as cmds

if OpenMaya.MGlobal.apiVersion() < 201600:

    envelope = OpenMayaMPx.cvar.MPxDeformerNode_envelope

    inputGeom = OpenMayaMPx.cvar.MPxDeformerNode_inputGeom

    outputGeom = OpenMayaMPx.cvar.MPxDeformerNode_outputGeom

else:

    inputGeom = OpenMayaMPx.cvar.MPxGeometryFilter_inputGeom

    envelope = OpenMayaMPx.cvar.MPxGeometryFilter_envelope

    outputGeom = OpenMayaMPx.cvar.MPxGeometryFilter_outputGeom

class BlendNode(OpenMayaMPx.MPxDeformerNode):

    kPluginNodeId = OpenMaya.MTypeId(0x00000002)

    aBlendMesh = OpenMaya.MObject()

    aBlendWeight = OpenMaya.MObject()

    def __init__(self):

        OpenMayaMPx.MPxDeformerNode.__init__(self)

    def deform(self, data, itGeo, localToWorldMatrix, mIndex):

        env = data.inputValue(envelope).asFloat()

        blendWeight = data.inputValue(BlendNode.aBlendWeight).asFloat()

        blendWeight *= env

        oBlendMesh = data.inputValue(BlendNode.aBlendMesh).asMesh()

        if oBlendMesh.isNull():

            return

        fnBlendMesh = OpenMaya.MFnMesh(oBlendMesh)

        blendPoints = OpenMaya.MPointArray()

        fnBlendMesh.getPoints(blendPoints)

        while not itGeo.isDone():

            pt = itGeo.position()

            w = self.weightValue(data, mIndex, itGeo.index())

            pt = pt + (blendPoints[itGeo.index()] - pt) * blendWeight * w

            itGeo.setPosition(pt)

            itGeo.next()

def creator():

    return OpenMayaMPx.asMPxPtr(BlendNode())

def initialize():

    tAttr = OpenMaya.MFnTypedAttribute()

    nAttr = OpenMaya.MFnNumericAttribute()

    BlendNode.aBlendMesh = tAttr.create('blendMesh', 'bm', OpenMaya.MFnData.kMesh)

    BlendNode.addAttribute( BlendNode.aBlendMesh )

    BlendNode.attributeAffects(BlendNode.aBlendMesh, outputGeom)

    BlendNode.aBlendWeight = nAttr.create('blendWeight', 'bw', OpenMaya.MFnNumericData.kFloat)

    nAttr.setKeyable(True)

    BlendNode.addAttribute(BlendNode.aBlendWeight)

    BlendNode.attributeAffects(BlendNode.aBlendWeight, outputGeom)

    # Make deformer weights paintable

    cmds.makePaintable('blendNode', 'weights', attrType='multiFloat', shapeMode='deformer')

def initializePlugin(obj):

    plugin = OpenMayaMPx.MFnPlugin(obj, 'Chad Vernon', '1.0', 'Any')

    try:

        plugin.registerNode('blendNode', BlendNode.kPluginNodeId, creator, initialize, OpenMayaMPx.MPxNode.kDeformerNode)

    except:

        raise RuntimeError, 'Failed to register node'

def uninitializePlugin(obj):

    plugin = OpenMayaMPx.MFnPlugin(obj)

    try:

        plugin.deregisterNode(BlendNode.kPluginNodeId)

    except:

        raise RuntimeError, 'Failed to deregister node'

# ------------------------------------------------------------------------------------------- #