I have a shapefile of 2' contours that I've converted into dwg format. I have an existing elevation field (double) in the shapefile that's populated with my elevation values. When it converts to dwg format there are some elevation values that don't carry over and populate as 0. These records all have an Entity field of Group instead of 3DPolyline. I've also tried the "Feature to 3D by Attribute" tool with the shapefile and it also assigns some of the contour lines to this Group entity and the elevation values don't carry over. There are approximately 50 of my 650 contour lines that don't carry over correctly. I've tried this with several shapefiles both in ArcGIS desktop 10.5 and ArcGIS Pro and the result is the same.

Why is this conversion dropping some of my elevation values and what can I do to correct this? Many of these dropped values are for a series of adjacent contour lines making it difficult to even extrapolate the missing values.

Highlighted are contours with elevations missing

Snapshot of the attribute table

  • it could be a text vs numeric format problem during the conversion or a problem with witch decimal separator (dot or comma) is expected. you should check if the missing elevation fit these case... – J.R Jan 25 at 16:13
  • We went through the shapefile and rounded all elevation values to whole integers in case this was the issue. We ended up with the same result of dropped elevation values. – MLasebikan Jan 25 at 16:23
  • Did you see a pattern in the dropped value (like range of elevation or below/above specific elevation) or closed contour vs open ? – J.R Jan 25 at 16:40
  • There doesn't appear to be a pattern. Many of those with issues are grouped together in range but there are other lines within that same range which are fine. Some open contours are fine and others are not. – MLasebikan Jan 25 at 17:15
  • It might struggling with multipart lines. Try converting to single part. – FelixIP Jan 25 at 18:10

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