python/api1/py1TorusField.py

from __future__ import division
#-
# ==========================================================================
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# The coded instructions, statements, computer programs, and/or related 
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#+

#
# Creation Date:   3 October 2006
#

########################################################################
# DESCRIPTION:
#
# Produces the dependency graph node "spTorusField".
# 
# The spTorusField node implements an attraction-and-repel field.
#
# The field repels all objects between itself and repelDistance attribute
# and attracts objects greater than attractDistance attribute from itself.  
# This will eventually result in the objects clustering in a torus shape
# around the field.
#
# See the torusFieldTest.py script for an example on using this node.
# The example creates a new field node and a particle object, and connects them together. 
#
########################################################################

from builtins import range
import math, sys
import maya.OpenMaya as OpenMaya
import maya.OpenMayaUI as OpenMayaUI
import maya.OpenMayaMPx as OpenMayaMPx
import maya.OpenMayaRender as OpenMayaRender

kPluginName = "spTorusField"
kPluginNodeId = OpenMaya.MTypeId(0x0008004f)

glRenderer = OpenMayaRender.MHardwareRenderer.theRenderer()
glFT = glRenderer.glFunctionTable()

def statusError(msg):
    sys.stderr.write("%s\n" % message)
    raise   # called from exception handlers only, reraise exception


# Node definition
class TorusField(OpenMayaMPx.MPxFieldNode):
    # Attributes
    # minimum distance from field at which repel is applied
    #
    aMinDistance = OpenMaya.MObject()

    # min distance from field at which the force attracts
    #
    aAttractDistance = OpenMaya.MObject()

    # max distance from field at which the force repels.
    #
    aRepelDistance = OpenMaya.MObject()

    # drag exerted on the attractRepel force.
    #
    aDrag = OpenMaya.MObject()

    # amplitude/magnitude of the swarm force.
    #
    aSwarmAmplitude = OpenMaya.MObject()

    # frequency of the swarm force.
    #
    aSwarmFrequency = OpenMaya.MObject()

    # phase of the swarm force.
    #
    aSwarmPhase = OpenMaya.MObject()


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


    def compute(self, plug, block):
        """
        Compute output force.
        """
        outputForce = OpenMayaMPx.cvar.MPxFieldNode_mOutputForce
        if not (plug == outputForce):
            return

        # get the logical index of the element this plug refers to.
        #
        try:
            multiIndex = plug.logicalIndex()
        except:
            statusError("ERROR in plug.logicalIndex.")

        # Get input data handle, use outputArrayValue since we do not
        # want to evaluate both inputs, only the one related to the
        # requested multiIndex. Evaluating both inputs at once would cause
        # a dependency graph loop.
        #
        inputData = OpenMayaMPx.cvar.MPxFieldNode_mInputData
        try:
            hInputArray = block.outputArrayValue(inputData)
        except:
            statusError("ERROR in hInputArray = block.outputArrayValue().")

        try:
            hInputArray.jumpToElement(multiIndex)
        except:
            statusError("ERROR: hInputArray.jumpToElement failed.")

        # get children of aInputData.
        #
        try:
            hCompond = hInputArray.inputValue()
        except:
            statusError("ERROR in hCompond=hInputArray.inputValue")

        inputPositions = OpenMayaMPx.cvar.MPxFieldNode_mInputPositions
        hPosition = hCompond.child(inputPositions)
        dPosition = hPosition.data()
        fnPosition = OpenMaya.MFnVectorArrayData(dPosition)
        try:
            points = fnPosition.array()
        except:
            statusError("ERROR in fnPosition.array(), not find points.")

        inputVelocities = OpenMayaMPx.cvar.MPxFieldNode_mInputVelocities
        hVelocity = hCompond.child(inputVelocities)
        dVelocity = hVelocity.data()
        fnVelocity = OpenMaya.MFnVectorArrayData(dVelocity)
        try:
            velocities = fnVelocity.array()
        except:
            statusError("ERROR in fnVelocity.array(), not find velocities.")

        inputMass = OpenMayaMPx.cvar.MPxFieldNode_mInputMass
        hMass = hCompond.child(inputMass)
        dMass = hMass.data()
        fnMass = OpenMaya.MFnDoubleArrayData(dMass)
        try:
            masses = fnMass.array()
        except:
            statusError("ERROR in fnMass.array(), not find masses.")

        # Compute the output force.
        #
        forceArray = OpenMaya.MVectorArray()
        useMaxDistSet = self.__useMaxDistanceValue(block)
        if useMaxDistSet:
            self.__applyMaxDist(block, points, velocities, masses, forceArray)
        else:
            self.__applyNoMaxDist(block, points, velocities, masses, forceArray)

        # get output data handle
        #
        try:
            hOutArray = block.outputArrayValue(outputForce)
        except:
            statusError("ERROR in hOutArray = block.outputArrayValue.")
        try:
            bOutArray = hOutArray.builder()
        except:
            statusError("ERROR in bOutArray = hOutArray.builder.")

        # get output force array from block.
        #
        try:
            hOut = bOutArray.addElement(multiIndex)
        except:
            statusError("ERROR in hOut = bOutArray.addElement.")

        fnOutputForce = OpenMaya.MFnVectorArrayData()
        try:
            dOutputForce = fnOutputForce.create(forceArray)
        except:
            statusError("ERROR in dOutputForce = fnOutputForce.create")

        # update data block with new output force data.
        #
        hOut.setMObject(dOutputForce)
        block.setClean(plug)


    def draw (self, view, path, style, status):
        """
        Draw a set of rings to symbolie the field. This does not override default icon, you can do that by implementing the iconBitmap() function
        """
        TORUS_PI = 3.14159265
        TORUS_2PI = 2.0 * TORUS_PI
        EDGES = 30
        SEGMENTS = 20

        view.beginGL()
        for j in range(SEGMENTS):
            glFT.glPushMatrix()
            glFT.glRotatef(360.0 * j / SEGMENTS, 0.0, 1.0, 0.0)
            glFT.glTranslatef(1.5, 0.0, 0.0)
            for i in range(EDGES):
                glFT.glBegin(OpenMayaRender.MGL_LINE_STRIP)
                p0 = TORUS_2PI * i / EDGES
                p1 = TORUS_2PI * (i+1) / EDGES
                glFT.glVertex2f(math.cos(p0), math.sin(p0))
                glFT.glVertex2f(math.cos(p1), math.sin(p1))
                glFT.glEnd()
            glFT.glPopMatrix()
        view.endGL()


    def getForceAtPoint(self, points, velocities, masses, forceArray, deltaTime):
        """
        This method is not required to be overridden, it is only necessary
        for compatibility with the MFnField function set.
        """
        block = forceCache()
        useMaxDistSet = self.__useMaxDistanceValue(block)
        if useMaxDistSet:
            self.__applyMaxDist(block, points, velocities, masses, forceArray)
        else:
            self.__applyNoMaxDist(block, points, velocities, masses, forceArray)


    def iconSizeAndOrigin(self, width, height, xbo, ybo):
        OpenMaya.MScriptUtil.setUint( width, 32 )
        OpenMaya.MScriptUtil.setUint( height, 32 )
        OpenMaya.MScriptUtil.setUint( xbo, 4 )
        OpenMaya.MScriptUtil.setUint( ybo, 4 )


    def iconBitmap(self, bitmap):
        OpenMaya.MScriptUtil.setUcharArray( bitmap, 0, 0x18 )
        OpenMaya.MScriptUtil.setUcharArray( bitmap, 4, 0x66 )
        OpenMaya.MScriptUtil.setUcharArray( bitmap, 8, 0xC3 )
        OpenMaya.MScriptUtil.setUcharArray( bitmap, 12, 0x81 )
        OpenMaya.MScriptUtil.setUcharArray( bitmap, 16, 0x81 )
        OpenMaya.MScriptUtil.setUcharArray( bitmap, 20, 0xC3 )
        OpenMaya.MScriptUtil.setUcharArray( bitmap, 24, 0x66 )
        OpenMaya.MScriptUtil.setUcharArray( bitmap, 28, 0x18 )


    # methods to compute output force.
    #
    def __applyNoMaxDist(self, block, points, velocities, masses, outputForce):
        """
        Compute output force in the case that the useMaxDistance is not set.
        """
        # points and velocities should have the same length. If not return.
        #
        if points.length() != velocities.length():
            return

        # clear the output force array
        #
        outputForce.clear()

        # get field parameters.
        #
        magValue = self.__magnitudeValue(block)
        minDist = self.__minDistanceValue(block)
        attractDist = self.__attractDistanceValue(block)
        repelDist = self.__repelDistanceValue(block)
        dragMag = self.__dragValue(block)
        swarmAmp = self.__swarmAmplitudeValue(block)

        # get owner's data. posArray may have only one point which is the centroid
        # (if this has owner) or field position(if without owner). Or it may have
        # a list of points if with owner and applyPerVertex.
        #
        posArray = self.__ownerPosition(block)

        fieldPosCount = posArray.length()
        receptorSize = points.length()

        # With this model,if max distance isn't set then we
        # also don't attenuate, because 1 - dist/maxDist isn't
        # meaningful. No max distance and no attenuation.
        #
        for ptIndex in range(receptorSize):
            forceV = OpenMaya.MVector(0.0,0.0,0.0)
            receptorPoint = points[ptIndex]

            # Apply from every field position to every receptor position.
            #
            distance = 0.0
            for i in range(fieldPosCount-1, -1, -1):
                difference = receptorPoint - posArray[i]
                distance = difference.length()

                if distance < minDist:
                    continue

                if distance <= repelDist:
                    forceV += difference * magValue
                elif distance >= attractDist:
                    forceV += -difference * magValue

            # Apply drag/swarm only if the object is inside the zone
            # the repulsion-attraction is pushing the object to.
            #
            if distance >= repelDist and distance <= attractDist:
                if dragMag > 0:
                    if fieldPosCount > 0:
                        dragForceV = velocities[ptIndex] * (-dragMag) * fieldPosCount
                        forceV += dragForceV

                if swarmAmp > 0:
                    frequency = self.__swarmFrequencyValue(block)
                    phase = OpenMaya.MVector(0.0, 0.0, frequency)

                    # Add swarm in here
                    #
                    for i in range(fieldPosCount-1, -1, -1):
                        difference = receptorPoint - posArray[i]
                        difference = (difference + phase) * frequency

                        noiseEffect = [ difference[i] for i in range(3) ]
                        if( (noiseEffect[0] < -2147483647.0) or
                            (noiseEffect[0] >  2147483647.0) or
                            (noiseEffect[1] < -2147483647.0) or
                            (noiseEffect[1] >  2147483647.0) or
                            (noiseEffect[2] < -2147483647.0) or
                            (noiseEffect[2] >  2147483647.0) ):
                            continue

                        noiseOut = self.__noiseFunction(noiseEffect)
                        swarmForce = OpenMaya.MVector(noiseOut[0] * swarmAmp,
                                                        noiseOut[1] * swarmAmp,
                                                        noiseOut[2] * swarmAmp)
                        forceV += swarmForce

            outputForce.append(forceV)


    def __applyMaxDist(self, block, points, velocities, masses, outputForce):
        """
        Compute output force in the case that the useMaxDistance is set.
        """
        # points and velocities should have the same length. If not return.
        #
        if points.length() != velocities.length():
            return

        # clear the output force array.
        #
        outputForce.clear()

        # get field parameters.
        #
        magValue = self.__magnitudeValue(block)
        attenValue = self.__attenuationValue(block)
        maxDist = self.__maxDistanceValue(block)
        minDist = self.__minDistanceValue(block)
        attractDist = self.__attractDistanceValue(block)
        repelDist = self.__repelDistanceValue(block)
        dragMag = self.__dragValue(block)
        swarmAmp = self.__swarmAmplitudeValue(block)

        # get owner's data. posArray may have only one point which is the centroid
        # (if this has owner) or field position(if without owner). Or it may have
        # a list of points if with owner and applyPerVertex.
        #
        posArray = self.__ownerPosition(block)

        fieldPosCount = posArray.length()
        receptorSize = points.length()

        for ptIndex in range(receptorSize):
            receptorPoint = points[ptIndex]

            # Apply from every field position to every receptor position.
            #
            forceV = OpenMaya.MVector(0,0,0)
            sumForceV = OpenMaya.MVector(0,0,0)
            for i in range(fieldPosCount-1, -1, -1):
                difference = receptorPoint-posArray[i]
                distance  = difference.length()

                if (distance < minDist or distance > maxDist):
                    continue

                if attenValue > 0.0:
                    force = magValue * (math.pow((1.0-(distance/maxDist)),attenValue))
                    forceV = difference * force
                elif (distance <= repelDist):
                    forceV = difference * magValue
                elif (distance >= attractDist):
                    forceV = -difference * magValue

                # Apply drag and swarm if the object is inside
                # the zone the repulsion-attraction is pushing the
                # object to, and if they are set.
                #
                if distance >= repelDist and distance <= attractDist:
                    if dragMag > 0:
                        if fieldPosCount > 0:
                            dragForceV = velocities[ptIndex] * (-dragMag) * fieldPosCount
                            forceV += dragForceV

                    if swarmAmp > 0:
                        frequency = self.__swarmFrequencyValue(block)
                        phase = OpenMaya.MVector(0.0, 0.0, frequency)

                        # Add swarm in here
                        #
                        for i in range(fieldPosCount-1, -1, -1):
                            difference = receptorPoint - posArray[i]
                            difference = (difference + phase) * frequency

                            noiseEffect = [ difference[i] for i in range(3) ]
                            if( (noiseEffect[0] < -2147483647.0) or
                                (noiseEffect[0] >  2147483647.0) or
                                (noiseEffect[1] < -2147483647.0) or
                                (noiseEffect[1] >  2147483647.0) or
                                (noiseEffect[2] < -2147483647.0) or
                                (noiseEffect[2] >  2147483647.0) ):
                                continue

                            noiseOut = self.__noiseFunction(noiseEffect)
                            swarmForce = OpenMaya.MVector(noiseOut[0] * swarmAmp,
                                                            noiseOut[1] * swarmAmp,
                                                            noiseOut[2] * swarmAmp)
                            forceV += swarmForce

                if (maxDist > 0.0):
                    forceV *= self.falloffCurve(distance/maxDist)
                sumForceV += forceV

            outputForce.append(sumForceV)


    def __ownerPosition(self, block):
        """
        If this field has an owner, get the owner's position array or
        centroid, then assign it to the ownerPosArray.
        If it does not have owner, get the field position in the world
        space, and assign it to the given array, ownerPosArray.
        """
        ownerPosArray = OpenMaya.MVectorArray()
        if self.__applyPerVertexValue(block):
            ownerPos = OpenMayaMPx.cvar.MPxFieldNode_mOwnerPosData
            try:
                hOwnerPos = block.inputValue(ownerPos)
            except:
                # get the field position in the world space
                # and add it into ownerPosArray.
                #
                worldPos = self.__getWorldPosition()
                ownerPosArray.append(worldPos)
            else:
                dOwnerPos = hOwnerPos.data()
                fnOwnerPos = OpenMaya.MFnVectorArrayData(dOwnerPos)
                try:
                    posArray = fnOwnerPos.array()
                except:
                    worldPos = self.__getWorldPosition()
                    ownerPosArray.append(worldPos)
                else:
                    # assign vectors from block to ownerPosArray.
                    #
                    for i in range(posArray.length()):
                        ownerPosArray.append(posArray[i])
        else:
            try:
                centroidV = self.__ownerCentroidValue(block)
            except:
                # get the field position in the world space.
                #
                worldPos = self.__getWorldPosition()
                ownerPosArray.append(worldPos)
            else:
                ownerPosArray.append(centroidV) 

        return ownerPosArray


    def __getWorldPosition(self):
        thisNode = self.thisMObject()
        fnThisNode = OpenMaya.MFnDependencyNode(thisNode)

        # get worldMatrix attribute.
        #
        worldMatrixAttr = fnThisNode.attribute("worldMatrix")

        # build worldMatrix plug, and specify which element the plug refers to.
        # We use the first element(the first dagPath of this field).
        #
        matrixPlug = OpenMaya.MPlug(thisNode, worldMatrixAttr)
        matrixPlug = matrixPlug.elementByLogicalIndex(0)

        # Get the value of the 'worldMatrix' attribute
        #
        try:
            matrixObject = matrixPlug.asMObject(matrixObject)
        except:
            statusError("TorusField.__getWorldPosition: get matrixObject")

        try:
            worldMatrixData = OpenMaya.MFnMatrixData(matrixObject)
        except:
            statusError("TorusField.__getWorldPosition: get worldMatrixData")

        try:
            worldMatrix = worldMatrixData.matrix()
        except:
            statusError("TorusField.__getWorldPosition: get worldMatrix")

        # assign the translate to the given vector.
        #
        return OpenMaya.MVector(worldMatrix(3, 0), worldMatrix(3, 1), worldMatrix(3, 2))


    def __noiseFunction(self, inNoise):
        """
        A noise function
        """
        # Shared data for noise computation
        #
        xlim = [ [0,0], [0,0], [0,0] ] # integer bound for point
        xarg = [0.0, 0.0, 0.0 ] # fractional part

        # Helper functions to compute noise
        #
        rand3a = lambda x,y,z: frand(67*(x)+59*(y)+71*(z))
        rand3b = lambda x,y,z: frand(73*(x)+79*(y)+83*(z))
        rand3c = lambda x,y,z: frand(89*(x)+97*(y)+101*(z))
        rand3d = lambda x,y,z: frand(103*(x)+107*(y)+109*(z))

        def frand(s):
            seed = s << 13^s
            return (1.0 - ((s*(s*s*15731+789221)+1376312589) & 0x7fffffff)/1073741824.0)

        def hermite(p0, p1, r0, r1, t):
            t2 = t * t
            t3 = t2 * t
            _3t2 = 3.0 * t2
            _2t3 = 2.0 * t3 

            return (p0*(_2t3-_3t2+1) + p1*(-_2t3+_3t2) + r0*(t3-2.0*t2+t) + r1*(t3-t2))

        def interpolate(i, n):
            f = [ 0.0, 0.0, 0.0, 0.0 ]
            if n == 0: # at 0, return lattice value
                f[0] = rand3a( xlim[0][i&1], xlim[1][i>>1&1], xlim[2][i>>2] )
                f[1] = rand3b( xlim[0][i&1], xlim[1][i>>1&1], xlim[2][i>>2] )
                f[2] = rand3c( xlim[0][i&1], xlim[1][i>>1&1], xlim[2][i>>2] )
                f[3] = rand3d( xlim[0][i&1], xlim[1][i>>1&1], xlim[2][i>>2] )
            else:
                n -= 1
                f0 = interpolate(i, n) # compute first half
                f1 = interpolate(i | 1<<n, n) # compute second half

                # use linear interpolation for slopes
                f[0] = (1.0 - xarg[n]) * f0[0] + xarg[n] * f1[0]
                f[1] = (1.0 - xarg[n]) * f0[1] + xarg[n] * f1[1]
                f[2] = (1.0 - xarg[n]) * f0[2] + xarg[n] * f1[2]

                # use hermite interpolation for values
                f[3] = hermite(f0[3], f1[3], f0[n], f1[n], xarg[n])

            return f

        xlim[0][0] = int(math.floor(inNoise[0]))
        xlim[0][1] = xlim[0][0] + 1
        xlim[1][0] = int(math.floor(inNoise[1]))
        xlim[1][1] = xlim[1][0] + 1
        xlim[2][0] = int(math.floor(inNoise[2]))
        xlim[2][1] = xlim[2][0] + 1

        xarg[0] = inNoise[0] - xlim[0][0]
        xarg[1] = inNoise[1] - xlim[1][0]
        xarg[2] = inNoise[2] - xlim[2][0]

        return interpolate(0, 3)


    # methods to get attribute value.
    #
    def __magnitudeValue(self, block):
        magnitude = OpenMayaMPx.cvar.MPxFieldNode_mMagnitude
        hValue = block.inputValue(magnitude)
        return hValue.asDouble()


    def __attenuationValue(self, block):
        attenuation = OpenMayaMPx.cvar.MPxFieldNode_mAttenuation
        hValue = block.inputValue(attenuation)
        return hValue.asDouble()


    def __maxDistanceValue(self, block):
        maxDistance = OpenMayaMPx.cvar.MPxFieldNode_mMaxDistance
        hValue = block.inputValue(maxDistance)
        return hValue.asDouble()


    def __useMaxDistanceValue(self, block):
        useMaxDistance = OpenMayaMPx.cvar.MPxFieldNode_mUseMaxDistance
        hValue = block.inputValue(useMaxDistance)
        return hValue.asBool()


    def __applyPerVertexValue(self, block):
        applyPerVertex = OpenMayaMPx.cvar.MPxFieldNode_mApplyPerVertex
        hValue = block.inputValue(applyPerVertex)
        return hValue.asBool()


    # methods to get attribute value of local attributes.
    #
    def __minDistanceValue(self, block):
        hValue = block.inputValue(TorusField.aMinDistance)
        return hValue.asDouble()


    def __attractDistanceValue(self, block):
        hValue = block.inputValue(TorusField.aAttractDistance)
        return hValue.asDouble()


    def __repelDistanceValue(self, block):
        hValue = block.inputValue(TorusField.aRepelDistance)
        return hValue.asDouble()


    def __dragValue(self, block):
        hValue = block.inputValue(TorusField.aDrag)
        return hValue.asDouble()


    def __swarmAmplitudeValue(self, block):
        hValue = block.inputValue(TorusField.aSwarmAmplitude)
        return hValue.asDouble()


    def __swarmFrequencyValue(self, block):
        hValue = block.inputValue(TorusField.aSwarmFrequency)
        return hValue.asDouble()


    def __swarmPhaseValue(self, block):
        hValue = block.inputValue(TorusField.aSwarmPhase)
        return hValue.asDouble()


    def __ownerCentroidValue(self, block):
        ownerCentroidX = OpenMayaMPx.cvar.MPxFieldNode_mOwnerCentroidX
        ownerCentroidY = OpenMayaMPx.cvar.MPxFieldNode_mOwnerCentroidY
        ownerCentroidZ = OpenMayaMPx.cvar.MPxFieldNode_mOwnerCentroidZ
        hValueX = block.inputValue(ownerCentroidX)
        hValueY = block.inputValue(ownerCentroidY)
        hValueZ = block.inputValue(ownerCentroidZ)
        return OpenMaya.MVector(hValueX.asDouble(),
                                    hValueY.asDouble(),
                                    hValueZ.asDouble())


############################################################################


# creator
def nodeCreator():
    return OpenMayaMPx.asMPxPtr(TorusField())


# initializer
def nodeInitializer():
    numAttr = OpenMaya.MFnNumericAttribute()

    # create the field basic attributes.
    #
    TorusField.aMinDistance = numAttr.create("minDistance", "mnd", OpenMaya.MFnNumericData.kDouble, 0.0)
    numAttr.setKeyable(True)
    try:
        TorusField.addAttribute(TorusField.aMinDistance)
    except:
        statusError("ERROR adding aMinDistance attribute.")

    TorusField.aAttractDistance = numAttr.create("attractDistance", "ad", OpenMaya.MFnNumericData.kDouble, 20.0)
    numAttr.setKeyable(True)
    try:
        TorusField.addAttribute(TorusField.aAttractDistance)
    except:
        statusError("ERROR adding aAttractDistance attribute.")

    TorusField.aRepelDistance = numAttr.create("repelDistance", "rd", OpenMaya.MFnNumericData.kDouble, 10.0)
    numAttr.setKeyable(True)
    try:
        TorusField.addAttribute(TorusField.aRepelDistance)
    except:
        statusError("ERROR adding aRepelDistance attribute.")

    TorusField.aDrag = numAttr.create("drag", "d", OpenMaya.MFnNumericData.kDouble, 0.0)
    numAttr.setKeyable(True)
    try:
        TorusField.addAttribute(TorusField.aDrag)
    except:
        statusError("ERROR adding aDrag attribute.")

    TorusField.aSwarmAmplitude = numAttr.create("swarmAmplitude", "samp", OpenMaya.MFnNumericData.kDouble, 0.0)
    numAttr.setKeyable(True)
    try:
        TorusField.addAttribute(TorusField.aSwarmAmplitude)
    except:
        statusError("ERROR adding aSwarmAmplitude attribute.")

    TorusField.aSwarmFrequency = numAttr.create("swarmFrequency", "sfrq", OpenMaya.MFnNumericData.kDouble, 1.0)
    numAttr.setKeyable(True)
    try:
        TorusField.addAttribute(TorusField.aSwarmFrequency)
    except:
        statusError("ERROR adding aSwarmFrequency attribute.")

    TorusField.aSwarmPhase = numAttr.create("swarmPhase", "sa", OpenMaya.MFnNumericData.kDouble, 0.0)
    numAttr.setKeyable(True)
    try:
        TorusField.addAttribute(TorusField.aSwarmPhase)
    except:
        statusError("ERROR adding aSwarmPhase attribute.")


# initialize the script plug-in
def initializePlugin(mobject):
    mplugin = OpenMayaMPx.MFnPlugin(mobject, "Autodesk", "1.0", "Any")
    try:
        mplugin.registerNode(kPluginName, kPluginNodeId, nodeCreator, nodeInitializer, OpenMayaMPx.MPxNode.kFieldNode)
    except:
        statusError("Failed to register node: %s" % kPluginName)


# uninitialize the script plug-in
def uninitializePlugin(mobject):
    mplugin = OpenMayaMPx.MFnPlugin(mobject)
    try:
        mplugin.deregisterNode(kPluginNodeId)
    except:
        statusError("Failed to deregister node: %s" % kPluginName)