Visualization Boundaries

One of the problems with doing visualizations is needing to mask out or hide the portion of the existing surface which is above the proposed surface. I’m working on a quick way to accomplish the task that doesn’t include manually extracting the surface border of the proposed surface and adding it to the existing surface. The code below is a start, it only works with one proposed surface boundary. Maybe if I get ambitious I’ll look at adding the ability to account for more than one boundary. The code does do multiple boundaries, but it doesn’t do it correctly in all cases.

Imports Autodesk.AutoCAD.Runtime
Imports Autodesk.Civil.Roadway.DatabaseServices
Imports Autodesk.AutoCAD.DatabaseServices
Imports Autodesk.AutoCAD.ApplicationServices
Imports AeccLandLib = Autodesk.AECC.Interop.Land
Imports Autodesk.AECC.Interop.UiLand
Imports Quux.C3DUtilities
Imports Autodesk.AutoCAD.Interop.Common
Imports Autodesk.Civil.Land.DatabaseServices

<Assembly: CommandClass(GetType(UpdatePolylineMaskBoundary))> 

Public Class UpdatePolylineMaskBoundary

    <CommandMethod("C3DRUpdatePolylineMaskBoundary")> _
    Public Sub UpdatePolylineMask()
        Try
            Dim oUtil As New Utilities
            Dim oType(0) As Type
            oType(0) = GetType(TinSurface)
            Dim oSurfSourceObjId As ObjectId = oUtil.GetEntityWithOptions("Select Proposed Surface: ", "Not a surface", oType)
            Dim oSurfExistObjId As ObjectId = oUtil.GetEntityWithOptions("Select Existing Surface: ", "Not a surface", oType)
            Dim db As Database = Application.DocumentManager.MdiActiveDocument.Database
            Dim tm As Autodesk.AutoCAD.DatabaseServices.TransactionManager = db.TransactionManager
            Using myT As Transaction = tm.StartTransaction

                'Get Civil 3D application, document and database
                Dim oCivil As New AeccAppConnection

                Dim obj As Object = oCivil.AeccDoc.ObjectIdToObject(CType(oSurfSourceObjId.OldIdPtr, Long))

                If TypeOf obj Is Autodesk.AECC.Interop.Land.AeccSurface Then
                    Dim oSurface As AeccLandLib.AeccSurface = obj
                    Dim oSurfExist As AeccLandLib.AeccSurface = oCivil.AeccDoc.ObjectIdToObject(CType(oSurfExistObjId.OldIdPtr, Long))
                    Dim objs() As Object = Nothing
                    objs = oSurface.ExtractBorder(Autodesk.AECC.Interop.Land.AeccDisplayOrientation.aeccDisplayOrientationPlan)
                    Dim i As Integer = 1
                    For Each obj In objs
                        Dim oBoundary As AcadEntity = obj
                        oSurfExist.Boundaries.Add(oBoundary, "C3DRBoundary-" & i, Autodesk.AECC.Interop.Land.AeccBoundaryType.aeccBoundaryHide, True, 0.1)
                        i = +1
                    Next

                End If
                myT.Commit()
            End Using


        Catch ex As Exception
            Dim oUtil As New Utilities
            oUtil.MessageWriter("Error in UpdatePolylineMask Sub")
        End Try
    End Sub

End Class

The program utilizes other code contained in the free version of the Sincpac and the Civil 3D Reminders Pack.