Civil 3D Alignment entities as DesignScript Geometry PolyCurve

Civil3D
1

Hi …
Using Python Script, CLR, .NET managed C3D DLL’s…
Is there a simple cast method to represent Autodesk.Civil.DatabaseServices.Alignment Entities as a DesignScript Geometry PolyCurve?
Thx for your patience,
K.

2

The C3DToolkit and Arkance Systems Node Library contains nodes to do that, can you use these? Or do you want to code it yourself?

3

Thx … I need to code it in python (referencing .NET) … please … if that’s ok …

4

I don’t speak Python, but here is some C# code (for a Dynamo node, not for a plug-in) that does the trick, you could rewrite it into Python:

using acAppServ = Autodesk.AutoCAD.ApplicationServices;
using acDbServ = Autodesk.AutoCAD.DatabaseServices;
using acGeom = Autodesk.AutoCAD.Geometry;
using acRuntime = Autodesk.AutoCAD.Runtime;
using cdDbServ = Autodesk.Civil.DatabaseServices;
using cdAppServ = Autodesk.Civil.ApplicationServices;
using dynAppServ = Autodesk.AutoCAD.DynamoApp.Services;
using dynACNodes = Autodesk.AutoCAD.DynamoNodes;
using dynCDNodes = Autodesk.Civil.DynamoNodes;

/// <summary>
/// Returns the Dynamo geometry of the Alignment (lines and arcs, spirals become short lines and MultipleSegments are returned as single line)
/// </summary>
[Dynamo.Graph.Nodes.NodeCategory("Query")]
public static PolyCurve GetDynamoGeometry(dynCDNodes.Alignment alignment)
{
    if (alignment == null) { return null; }

    cdDbServ.Alignment alignmentCD = alignment.InternalDBObject as cdDbServ.Alignment;
    List<Curve> curves = new List<Curve>();

    try
    {
        dynACNodes.Document document = dynACNodes.Document.Current;
        using (dynAppServ.DocumentContext ctx = new dynAppServ.DocumentContext(document.AcDocument))
        {
            acDbServ.Transaction tr = ctx.Transaction; // using, disposing or submit a Transaction results in Fatal Error

            if (alignmentCD.Entities.Count != 0)
            {

                for (int i = 0; i < alignmentCD.Entities.Count; i++)
                {
                    cdDbServ.AlignmentEntity aeEnt = alignmentCD.Entities.GetEntityByOrder(i); // Entities in an Alignment are not in order.

                    if (aeEnt.EntityType == cdDbServ.AlignmentEntityType.Arc)
                    {
                        cdDbServ.AlignmentArc aaEnt = (cdDbServ.AlignmentArc)aeEnt;
                        // Clockwise arcs become the remainder of a circle, so draw the opposite.
                        if (aaEnt.Clockwise == true)
                        {
                            curves.Add(Arc.ByCenterPointStartPointEndPoint(Point.ByCoordinates(aaEnt.CenterPoint.X, aaEnt.CenterPoint.Y), Point.ByCoordinates(aaEnt.EndPoint.X, aaEnt.EndPoint.Y), Point.ByCoordinates(aaEnt.StartPoint.X, aaEnt.StartPoint.Y)));
                        }
                        else
                        {
                            curves.Add(Arc.ByCenterPointStartPointEndPoint(Point.ByCoordinates(aaEnt.CenterPoint.X, aaEnt.CenterPoint.Y), Point.ByCoordinates(aaEnt.StartPoint.X, aaEnt.StartPoint.Y), Point.ByCoordinates(aaEnt.EndPoint.X, aaEnt.EndPoint.Y)));
                        }
                    }

                    else if (aeEnt.EntityType == cdDbServ.AlignmentEntityType.Line)
                    {
                        cdDbServ.AlignmentLine alEnt = (cdDbServ.AlignmentLine)aeEnt;
                        curves.Add(Line.ByStartPointEndPoint(Point.ByCoordinates(alEnt.StartPoint.X, alEnt.StartPoint.Y), Point.ByCoordinates(alEnt.EndPoint.X, alEnt.EndPoint.Y)));
                    }
                    else if (aeEnt.EntityType == cdDbServ.AlignmentEntityType.MultipleSegments)
                    {
                        cdDbServ.AlignmentMultipleSegments alEnts = (cdDbServ.AlignmentMultipleSegments)aeEnt;

                        curves.Add(Line.ByStartPointEndPoint(Point.ByCoordinates(alEnts.StartPoint.X, alEnts.StartPoint.Y), Point.ByCoordinates(alEnts.EndPoint.X, alEnts.EndPoint.Y)));
                    }
                    else
                    {
                        cdDbServ.AlignmentCurve ac = (cdDbServ.AlignmentCurve)aeEnt;
                        if (ac != null)
                        {
                            Point start = Point.ByCoordinates(ac.StartPoint.X, ac.StartPoint.Y);

                            // Divide the curve and loop through points on the alignment between startstation and endstation.
                            double divideLength = ac.Length / 10.0;
                            for (double j = ac.StartStation + divideLength; j < ac.EndStation; j += divideLength)
                            {
                                acGeom.Point3d endCD = alignmentCD.GetPointAtDist(j);
                                Point end = Point.ByCoordinates(endCD.X, endCD.Y);
                                curves.Add(Line.ByStartPointEndPoint(start, end));
                                start = end;
                            }

                            // Add last part to the endpoint of the curve.
                            Point endCurve = Point.ByCoordinates(ac.EndPoint.X, ac.EndPoint.Y);
                            if (global::Functions.Numbers.IsSameValue(start.DistanceTo(endCurve), 0.0) == false)
                            {
                                curves.Add(Line.ByStartPointEndPoint(start, endCurve));
                            }
                        }
                    }
                }
            }
        }
    }
    catch (System.Exception ex) { GenericException.Logging.ExceptionLog.Log(ex); }

    return PolyCurve.ByJoinedCurves(curves);
}
5

Excellent - Thank You : )