Corridor Feature Line Z-value distortion at intersections with another corridor

[rampseeker]

Hello,

I am extracting corridor feature lines from a corridor using the following code

var flMap = baseline.MainBaselineFeatureLines.FeatureLineCollectionMap;
foreach (var flc in flMap)
{
    if (!flc.FeatureLineCodeInfo.CodeName.Equals(targetCode, StringComparison.OrdinalIgnoreCase))
        continue;
    
    foreach (CorridorFeatureLine fl in flc)
    {
        try
        {
            ObjectId flId = fl.ExportAsGradingFeatureLine(siteId, true);
            var autoFL = tr.GetObject(flId, OpenMode.ForWrite) as AutoCorridorFeatureLine;
            if (autoFL != null)
            {
                autoFL.Layer = "C-TOPO-FEAT";
                ed.WriteMessage($"\nFeatureLine extracted: {autoFL.CorridorName} -> Site '{alignment.SiteId}'");
                extractedFeatureLines.Add(flId);
            }
        }
        catch (System.Exception ex)
        {
            ed.WriteMessage($"\nExport failed: {alignment.Name} - {ex.Message}");
        }
    }
}

The feature lines are generated successfully in most cases.
However, at the points where these feature lines intersect with feature lines from another corridor, the Z values of the feature lines become distorted and produce incorrect geometry 

I am not sure why this distortion occurs.

1. What causes this kind of Z-value distortion at the intersections of corridor feature lines? and

2. Is there a recommended method to avoid or fix this issue?

Thank you in advance.

[ka-kei_leung · Accepted solution]

It is recommended to store the Feature Lines from different corridors in different Site. As the Z values of the Feature Line under the same site with the same X and Y coordinates will become the same.