If polyline is type lwpolyline or polyline
{code}
Dim Coords As Point3dCollection = New Point3dCollection
For i as integer = 1 To SelPoly.NumberOfVertices
Coords.Add(SelPoly.GetPoint3dAt(i - 1))
Next i
{code}
If selected poylline is poyliline2d then
{code}
Dim Coords As Point3dCollection = New Point3dCollection
For Each vId As DatabaseServices.ObjectId In SelPoly2d
Dim v2d As DatabaseServices.Vertex2d = DirectCast(myTrans.GetObject(vId, DatabaseServices.OpenMode.ForRead), DatabaseServices.Vertex2d)
Coords.Add(CType(v2d.Position, Point3d))
Next
{code}
Now you can easy get every vertex in drawing order at integer parametar i.
xi = Coords(i).x
yi = Coords(i).y
zi = Coords(i).z
i=0 to Coords.count-1