Imports System

Imports System.Collections.Generic

Imports System.Linq

Imports System.IO

Public Module Module1

    Public Sub Main()

        Dim data As String = "

o Layer_1_Hull

.

.

.

o Layer_2_Mainsail                         

v 13.747500 283.669006 411.285187          

v 13.747500 283.669006 411.275177

v 13.797300 283.483002 411.275177

vt 0.900824 0.386317                       

vt 0.900895 0.386336

vt 0.871146 0.496693

vt 0.871075 0.496673                       

vn -0.9660 -0.2587 0.0000

vn -0.9660 0.2587 0.0000

vn -0.7071 0.7072 0.0000

vn -0.2592 0.9658 0.0000"

'--------

'Important part is here

'---------

        Dim lines = ReadLines(data).

            SkipWhile(Function(line) Not line.StartsWith("o " + "Layer_2_Mainsail")).

            SkipWhile(Function(line) Not line.StartsWith("vt ")).

            TakeWhile(Function(line) Not line.StartsWith("vn "))

'---------

        For Each line As String In lines

            Console.WriteLine(line)         

        Next

    End Sub

    'Replicate the File.ReadLines() method for use with Fiddle

    Public Iterator Function ReadLines(input as String) As IEnumerable(Of String)

        Dim rdr As New StringReader(input)

        Dim line As String = rdr.ReadLine()             

        While line IsNot Nothing 

            Yield line

            line = rdr.ReadLine()

        End While

    End Function    

End Module