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