Export mesh from Rhino layer by layer

rhinoExport.vb

Option Explicit
 
 Sub ExportLayerObjects
 
   ' Declare local variables
   Dim strPath, strFile
   Dim arrLayers, strLayer
   Dim arrSelected
 
   ' Get the path to and name of the current document.
   ' Surround with double-quotes in case path includes spaces.
   strPath = Chr(34) & Rhino.DocumentPath & Rhino.DocumentName & Chr(34)
 
   ' Get names of all layers
   arrLayers = Rhino.LayerNames
 
   ' Disable redrawing
   Rhino.EnableRedraw False
 
   ' Process each layer
   For Each strLayer In arrLayers
 
     ' Unselect all  
     Rhino.Command "_-SelNone", 0
 
     ' Select all objects on layer. Surround layer name
     ' with double-quotes in case it includes spaces.
     Rhino.Command "_-SelLayer " & Chr(34) & strLayer & Chr(34), 0
 
     ' Make sure some objects were selected
     arrSelected = Rhino.SelectedObjects
     If IsArray(arrSelected) Then
 
       ' Generate a modified path string
       ' that includes the layer name
       strFile = strPath
       strFile = Replace(strFile, ".3dm", "_" & strLayer & ".3dm")
 
       ' Export the selected objects
       Rhino.Command "_-Export " & strFile, 0
 
     End If
   Next
 
   ' Unselect all
   Rhino.Command "_-SelNone", 0
 
   ' Enable redrawing
   Rhino.EnableRedraw True
 
 End Sub