The ArcGIS Geodatabase model allows for the storage of true curves in the form of Bezier, Circular, and Eliptical Arcs. Some software (including the spatial query in ESRI's own ArcGIS Server 9.2 doesn't work well with these departures from the basic linear features described as a list of x,y coordinate pair vertices.
This script can be used to detect non-linear segments in a geodatabase feature class. Object ID's are output to a text file. Run it from ArcMap, it will work on the first layer (position 0 in the TOC).
The fastest way to bulk convert these curves to line-based segments is to export to a shapefile, although it is possible to operate on the geometry programatically so you can avoid exporting and reloading your data.
Public Sub findNonLinearSegments()
Open "c:/temp/nonlineargeogeometry.txt" For Output As #1
Dim pMxDoc As IMxDocument Dim pMap As IMap Set pMxDoc = ThisDocument Set pMap = pMxDoc.FocusMap
Dim pSrcLayer As IFeatureLayer Dim pSrcFeatureClass As IFeatureClass Dim pSrcFeatureCursor As IFeatureCursor Dim pSrcFeature As IFeature Dim pPolygon As IPolygon Dim pSegCol As ISegmentCollection Dim pArea As IArea Dim pQF As IQueryFilter
Set pSrcLayer = pMap.Layer(0) '(Source Layer is first layer in TOC) Set pSrcFeatureClass = pSrcLayer.FeatureClass
Set pQF = New QueryFilter pQF.WhereClause = ""
Set pSrcFeatureCursor = pSrcLayer.Search(pQF, True) Set pSrcFeature = pSrcFeatureCursor.NextFeature
'iterate through quad features (which are all polygons with 5 points) Do Until pSrcFeature Is Nothing
Set pPolygon = pSrcFeature.Shape Set pSegCol = pPolygon Dim pEnumSegs As IEnumSegment Dim pSeg As ISegment Dim partindex As Long Dim segindex As Long
Set pEnumSegs = pSegCol.EnumSegments pEnumSegs.Next pSeg, partindex, segindex Do Until pSeg Is Nothing If TypeOf pSeg Is IBezierCurve Or TypeOf pSeg Is IEllipticArc Or TypeOf pSeg Is ICircularArc Then Print #1, pSrcFeature.OID & " " & pSrcLayer.Name Exit Do Else Debug.Print pSrcFeature.OID End If
'Set pSeg = pEnumSegs.Next pEnumSegs.Next pSeg, partindex, segindex Loop Set pSrcFeature = pSrcFeatureCursor.NextFeature Loop Close #1 End Sub
