maya api : while importing prompts error

[blossom ghuntla]

Hello All,

I autodidact basic python, basic maya.cmds, basic qt just for the sake of learning to create a deformer and i am not doing good at all

i referred https://help.autodesk.com/view/MAYAUL/2017/ENU/?guid=__cpp_ref_y_twist_node_2y_twist_node_8cpp_example_html

# defTwist.py

import sys

import maya.OpenMayaMPx as OpenMayaMPx

import maya.OpenMaya as OpenMaya

import maya.cmds as cmds

import math

# Plug-in information:

kPluginNodeName = "twistDeformer"     # The name of the node.

kPluginNodeId = OpenMaya.MTypeId( 0xBEEF8 ) # A unique ID associated to this node type.

# Some global variables were moved from MPxDeformerNode to MPxGeometryFilter.

# Set som constants to the proper C++ cvars based on the API version

kApiVersion = cmds.about(apiVersion=True)

if kApiVersion < 201600:

kInput = OpenMayaMPx.cvar.MPxDeformerNode_input

kInputGeom = OpenMayaMPx.cvar.MPxDeformerNode_inputGeom

kOutputGeom = OpenMayaMPx.cvar.MPxDeformerNode_outputGeom

kEnvelope = OpenMayaMPx.cvar.MPxDeformerNode_envelope

else:

kInput = OpenMayaMPx.cvar.MPxGeometryFilter_input

kInputGeom = OpenMayaMPx.cvar.MPxGeometryFilter_inputGeom

kOutputGeom = OpenMayaMPx.cvar.MPxGeometryFilter_outputGeom

kEnvelope = OpenMayaMPx.cvar.MPxGeometryFilter_envelope

class MyDeformerNode(OpenMayaMPx.MPxDeformerNode):

    

# Static variable(s) which will later be replaced by the node's attribute(s).

twistYAttr = OpenMaya.MObject()

def __init__(self):

''' Constructor. '''

# (!) Make sure you call the base class's constructor.

OpenMayaMPx.MPxDeformerNode.__init__(self)

def deform(self, pDataBlock, pGeometryIterator, pLocalToWorldMatrix, pGeometryIndex):

''' Deform each vertex using the geometry iterator. '''

# The envelope determines the overall weight of the deformer on the mesh.

# The envelope is obtained via the OpenMayaMPx.cvar.MPxDeformerNode_envelope (pre Maya 2016) or

# OpenMayaMPx.cvar.MPxGeometryFilter_envelope (Maya 2016) variable.

# This variable and others like it are generated by SWIG to expose variables or constants declared in C++ header files. 

envelopeAttribute = kEnvelope

envelopeValue = pDataBlock.inputValue( envelopeAttribute ).asFloat()

# Get the value of the mesh twist node attribute.

twistYAttribute = pDataBlock.inputValue( MyDeformerNode.twistYAttr )

twistYAttributeType = meshInflationHandle.asDouble()

# Get the input mesh from the datablock using our getDeformerInputGeometry() helper function.     

inputGeometryObject = self.getDeformerInputGeometry(pDataBlock, pGeometryIndex)

# Obtain the list of normals for each vertex in the mesh.

normals = OpenMaya.MFloatVectorArray()

meshFn = OpenMaya.MFnMesh( inputGeometryObject )

meshFn.getVertexNormals( True, normals, OpenMaya.MSpace.kObject )

def getDeformerInputGeometry(self, pDataBlock, pGeometryIndex):

'''

Obtain a reference to the input mesh. This mesh will be used to compute our bounding box, and we will also require its normals.

We use MDataBlock.outputArrayValue() to avoid having to recompute the mesh and propagate this recomputation throughout the 

Dependency Graph.

OpenMayaMPx.cvar.MPxDeformerNode_input and OpenMayaMPx.cvar.MPxDeformerNode_inputGeom (for pre Maya 2016) and 

OpenMayaMPx.cvar.MPxGeometryFilter_input and OpenMayaMPx.cvar.MPxGeometryFilter_inputGeom (Maya 2016) are SWIG-generated 

variables which respectively contain references to the deformer's 'input' attribute and 'inputGeom' attribute.   

'''

inputAttribute = OpenMayaMPx.cvar.MPxGeometryFilter_input

inputGeometryAttribute = OpenMayaMPx.cvar.MPxGeometryFilter_inputGeom

inputHandle = pDataBlock.outputArrayValue( inputAttribute )

inputHandle.jumpToElement( pGeometryIndex )

inputGeometryObject = inputHandle.outputValue().child( inputGeometryAttribute ).asMesh()

return inputGeometryObject

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

# Plug-in initialization.

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

def nodeCreator():

''' Creates an instance of our node class and delivers it to Maya as a pointer. '''

return OpenMayaMPx.asMPxPtr( MyDeformerNode() )

def nodeInitializer():

''' Defines the input and output attributes as static variables in our plug-in class. '''

# The following MFnNumericAttribute function set will allow us to create our attributes.

numericAttributeFn = OpenMaya.MFnNumericAttribute()

#==================================

# INPUT NODE ATTRIBUTE(S)

#==================================

# Define a mesh inflation attribute, responsible for actually moving the vertices in the direction of their normals.

MyDeformerNode.meshInflationAttribute = numericAttributeFn.create( 'ytwist', 'yt', OpenMaya.MFnNumericData.kDouble, 10.0 )

numericAttributeFn.setDefault(0.0)

numericAttributeFn.setKeyable(True)

MyDeformerNode.addAttribute( MyDeformerNode.twistYAttribute )

''' The input geometry node attribute is already declared in OpenMayaMPx.cvar.MPxGeometryFilter_inputGeom '''

#==================================

# OUTPUT NODE ATTRIBUTE(S)

#==================================

''' The output geometry node attribute is already declared in OpenMayaMPx.cvar.MPxGeometryFilter_outputGeom '''

#==================================

# NODE ATTRIBUTE DEPENDENCIES

#==================================

# If any of the inputs change, the output mesh will be recomputed.

print dir(OpenMayaMPx.cvar)

MyDeformerNode.attributeAffects( MyDeformerNode.twistYAttr, kOutputGeom )

    

def initializePlugin( mobject ):

''' Initialize the plug-in '''

mplugin = OpenMayaMPx.MFnPlugin( mobject )

try:

    mplugin.registerNode( kPluginNodeName, kPluginNodeId, nodeCreator,

                          nodeInitializer, OpenMayaMPx.MPxNode.kDeformerNode )

except:

    sys.stderr.write( 'Failed to register node: ' + kPluginNodeName )

    raise

    

def uninitializePlugin( mobject ):

''' Uninitializes the plug-in '''

mplugin = OpenMayaMPx.MFnPlugin( mobject )

try:

    mplugin.deregisterNode( kPluginNodeId )

except:

    sys.stderr.write( 'Failed to deregister node: ' + kPluginNodeName )

    raise

and tried translating losing all hope i searched online for twist python reference below is the link 

https://download.autodesk.com/us/maya/2009help/API/y_twist_node_8py-example.html

I want this so badly i dont get it why its not executing and when i try executing 

https://help.autodesk.com/view/MAYAUL/2017/ENU/?guid=__files_GUID_10CE99A6_2C32_49E1_85ED_2E2F6782CF23_htm

works like a charm

let me know if any correction are needed in the script or anything i need to study, as i am interested in learning api

// Error: file: /builds/maya_runtime/6b3b073194/scripts/others/pluginWin.mel line 909: type object 'MyDeformerNode' has no attribute 'twistYAttribute'

# Traceback (most recent call last):

#   File "/u/bghu/PycharmProjects/scripts/twistDeformer.py", line 104, in nodeInitializer

#     MyDeformerNode.addAttribute( MyDeformerNode.twistYAttribute )

# AttributeError: type object 'MyDeformerNode' has no attribute 'twistYAttribute' // 

// Warning: file: /builds/maya_runtime/6b3b073194/scripts/others/pluginWin.mel line 909: Failed to call script creator function // 

[Robert White]

It looks like in some of your code you're referencing it as `twistYAttribute` but in other places as `twistYAttr` which appears to be the correct spelling.

[blossom ghuntla]

# Warning: Skipped polyCylinder1 since it was not deformable. # 

# Error: (kInvalidParameter): Object is incompatible with this method

# Traceback (most recent call last):

#   File "/u/bghu/PycharmProjects/scripts/twistDeformer.py", line 50, in deform

#     twistYAttribute = pDataBlock.inputValue( MyDeformerNode.twistYAttr )

# RuntimeError: (kInvalidParameter): Object is incompatible with this method # 

# Result: [u'twistDeformer1'] # 

// Error: (kInvalidParameter): Object is incompatible with this method

# Traceback (most recent call last):

#   File "/u/bghu/PycharmProjects/scripts/twistDeformer.py", line 50, in deform

#     twistYAttribute = pDataBlock.inputValue( MyDeformerNode.twistYAttr )

# RuntimeError: (kInvalidParameter): Object is incompatible with this method // 

Thank you that fixed the crashing issue

But now i am facing a new error

[blossom ghuntla]

fixed the issue

while not pGeometryIterator.isDone():
point = pGeometryIterator.position()
ff = magnitude*point.y*envelopeValue
if ff != 0.0:
cct = math.cos(ff)
cst = math.sin(ff)
tt = point.x*cct - point.z*cst
point.z = point.x*cst +point.z*cct
point.x=tt
pGeometryIterator.setPosition(point)
pGeometryIterator.next()

why it wasn't working for me was the last 2 lines causing the while loop to iterate over and over again(the popular infinite loop)

so its done now i can proceed further by working on new deformers

Thank you for you help and i have even attached the code for checking purpose

--
You received this message because you are subscribed to a topic in the Google Groups "Python Programming for Autodesk Maya" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/python_inside_maya/-gIdP7BFhbE/unsubscribe.
To unsubscribe from this group and all its topics, send an email to python_inside_m...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/python_inside_maya/4fd22e6d-2b24-4614-9b09-a3609969d3f3%40googlegroups.com.