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ConstructOffset in Python with ArcObjects

Question asked by wimdevalk_nl on Dec 4, 2014

I'm scripting with Python and ArcPy in ArcGIS 10.2. I want to create a offsetline from a polylineZ. ArcPy doesn't have such a function so far I know. Therefore I'm trying to use ArcObjects within my Pythonscript. My scripting is based on following VB.Net code:

 

pConstructCurve = New Polyline
         pConstructCurve.ConstructOffset(pInPolyline, dOffset, esriConstructOffsetEnum.esriConstructOffsetRounded + 
                 esriConstructOffsetEnum.esriConstructOffsetSimple)
         ConstructOffset = pConstructCurve

I use snippets.py from Mark Cederholm for creating and using ArcObjects. That's going very well with exception of the statement pConstructCurve.ConstructOffset. A part of my code is:

 

pFeatureSelection = Snippits.CType(pFeatureLayer, esriCarto.IFeatureSelection)
pSelectionSet = pFeatureSelection.SelectionSet
pCursor = pSelectionSet.Search (None, False)
pFeatureCursor = Snippits.CType(pCursor, esriGeoDatabase.IFeatureCursor)
pFeat = pFeatureCursor.NextFeature()

while pFeat:

    # Maak offsetlijnen:
    dOffset = 2.00

    # Maak offsetlijn aan de rechterkant
    pPolyline = Snippits.NewObj(esriGeometry.Polyline, esriGeometry.IPolyline)
    pConstructCurve = Snippits.CType(pPolyline, esriGeometry.IConstructCurve)

    pInPolyline = Snippits.CType(pFeat.Shape, esriGeometry.IPolyline)

    iOffsetHow = esriGeometry.esriConstructOffsetMitered + esriGeometry.esriConstructOffsetSimple

    pConstructCurve.ConstructOffset(pInPolyline, dOffset, iOffsetHow)


    pNewPolyline = Snippits.CType(pConstructCurve, esriGeometry.IPolyline)

    pNewFeature = pFCOffsetLine.CreateFeature()
    iLijnsoortField = pNewFeature.Fields.FindField(sLijnsoortFieldName)
    pNewFeature.Value[iLijnsoortField] = "rechts"
    pNewFeature.Store

The statement pConstructCurve.ConstructOffset doesn't return anything of a couple of points (most two) with faulty X and Y values. Sometimes an error message appears: "The Geometry has no Z values"

 

Questions:

- Is it right that AcPy doesn't have such a function?

- What is wrong in my scripting?

 

Best regards,

 

Wim

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