I want create spot elevation in the intersection point wall and toposurface. What i do wrong?
Private Function CalculateLineAboveFloor(doc As Document, wWall As Wall) As Line
' Find a 3D view to use for the ReferenceIntersector constructor
Dim collector As New FilteredElementCollector(doc)
Dim isNotTemplate As Func(Of View3D, Boolean) = Function(v3) Not (v3.IsTemplate)
Dim view3D As View3D = collector.OfClass(GetType(View3D)).Cast(Of View3D)().First(isNotTemplate)
' Use the center of the skylight bounding box as the start point.
Dim box As BoundingBoxXYZ = wWall.BoundingBox(view3D)
Dim center As XYZ = box.Min.Add(box.Max).Multiply(0.5)
' Project in the negative Z direction down to the floor.
Dim rayDirection As New XYZ(0, 0, -1)
'Dim filter As New ElementClassFilter(GetType(Floor))
' Dim filter As New ElementClassFilter(GetType(TopographySurface))
Dim filter As New ElementClassFilter(GetType(TopographySurface))
'Dim refIntersector As New ReferenceIntersector(filter, FindReferenceTarget.Face, view3D)
Dim refIntersector As New ReferenceIntersector(filter, FindReferenceTarget.Mesh, view3D)
Dim referenceWithContext As ReferenceWithContext = refIntersector.FindNearest(center, rayDirection)
Dim reference As Reference = referenceWithContext.GetReference()
Dim intersection As XYZ = reference.GlobalPoint
' Create line segment from the start point and intersection point.
Dim result As Line = Line.CreateBound(center, intersection)
'Create spot elevation
Dim p As XYZ = result.GetEndPoint(1)
Dim bEnd As XYZ = p.Add(New XYZ(0, 1, 4))
Dim EndPnt As XYZ = p.Add(New XYZ(0, 2, 4))
Dim curView As DB.View = doc.ActiveView
Dim rp As New Reference(curView)
Dim sd As SpotDimension = doc.Create.NewSpotElevation(curView, reference, p, bEnd, EndPnt, p, True)
Return result
End Function
