0_set resolution on previously saved scene.py

#set up resolution
masterVolumeNode = slicer.mrmlScene.GetFirstNodeByClass("vtkMRMLScalarVolumeNode")
import itertools
imagespacing = [spacing]*3
masterVolumeNode.SetSpacing(imagespacing)#assign resolution to the volume
volumeScalarRange = masterVolumeNode.GetImageData().GetScalarRange()

#set up segmentatin node
segmentationNode = slicer.util.getNode('Segmentation')

segmentationDisplayNode=segmentationNode.GetDisplayNode()
#if previously saved
segmentEditorNode = slicer.util.getNode('SegmentEditor')

# Create segment editor to get access to effects
segmentEditorWidget = slicer.qMRMLSegmentEditorWidget()
segmentEditorWidget.setMRMLScene(slicer.mrmlScene)#connect widget to scene
segmentEditorWidget.setMRMLSegmentEditorNode(segmentEditorNode)#connect segment editor to editor widget
segmentEditorWidget.setSegmentationNode(segmentationNode)#connect segmentation node
segmentEditorWidget.setMasterVolumeNode(masterVolumeNode)#connect master node

# Compute bone threshold value automatically
import vtkITK
ME_thresholdCalculator = vtkITK.vtkITKImageThresholdCalculator()
ME_thresholdCalculator.SetInputData(masterVolumeNode.GetImageData())
ME_thresholdCalculator.SetMethodToMaximumEntropy()
ME_thresholdCalculator.Update()
Maxentval = ME_thresholdCalculator.GetThreshold()

ISO_thresholdCalculator = vtkITK.vtkITKImageThresholdCalculator()
ISO_thresholdCalculator.SetInputData(masterVolumeNode.GetImageData())
ISO_thresholdCalculator.SetMethodToIsoData()
ISO_thresholdCalculator.Update()
ISOval = ISO_thresholdCalculator.GetThreshold()

FIDNode1 = getNode(ID+" TM")
FIDNode2 = getNode(ID+" RW")
FIDNode3 = getNode(ID+" CA")
FIDNode4 = getNode(ID+" EC")

FIDNode5 = slicer.mrmlScene.AddNewNodeByClass("vtkMRMLMarkupsFiducialNode")
FIDNode5.SetName(ID+"ECandTMmrk_outline")#creates a new segmentation

FIDNode5 = getNode(ID+"ECandTMmrk_outline")