Summary: Demonstrates how to rename layers in a hierarchical manner using RhinoScript.

When the Rhino 4.0 file saves to Rhino 3.0 format, all hierarchical layering is lost. Is there a way to rename layers to reflect their hierarchial order? For example, Interior-boat > Dimensions becomes “Interior-boat-Dimensions”.

The following sample RhinoScript code demonstrates how to rename layers in a hierarchical manner using RhinoScript. Users wanting to save to Rhino 3.0 can run the SetHierarchicalLayerNames subroutine before saving and then run Undo after saving to roll back the layer changes.

 Option Explicit
 
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 ' SetHierarchicalLayerNames
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 Sub SetHierarchicalLayerNames()
 
   ' String that separates layer names
   Const separator = "-"
 
   ' Get all of the layer names.
   Dim all_layer
   all_layer = Rhino.LayerNames
 
   ' If only one layer, just bail.
   If UBound(all_layer) = 0 Then Exit Sub
 
   ' Build an array of layers who have no parent
   ' and that are from a reference file.
   Dim root_layers(), layer_count
   layer_count = 0  
   Dim layer_name, parent_layer
   For Each layer_name In all_layer
     parent_layer = Rhino.ParentLayer(layer_name)
     If IsNull(parent_layer) And Rhino.IsLayerReference(layer_name) = vbFalse Then
       ReDim Preserve root_layers(layer_count)
       root_layers(layer_count) = layer_name
       layer_count = layer_count + 1
     End If
   Next
 
   ' If the lists are the same size, then there are not
   ' child layers. So, just bail.
   If UBound(all_layer) = UBound(root_layers) Then Exit Sub
 
   ' Process the list of parentless layers    
   ProcessLayerList root_layers, separator
 
 End Sub
 
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 ' ProcessLayerList
 ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 Sub ProcessLayerList(layer_list, separator)
   ' Process each layer in the array. Note,
   ' this is a recursive function.
   Dim layer_name, layer_children
   For Each layer_name In layer_list
     ProcessLayer layer_name, separator
   Next
 End Sub 
 
 ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 ' ProcessLayer
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 Sub ProcessLayer(layer_name, separator)
 
   ' Get the layer's parent
   Dim parent_layer, renamed_layer, layer_children
   parent_layer = Rhino.ParentLayer(layer_name)
 
   ' If the layer has a parent, then modify its name
   ' to include its parent name.
   If IsNull(parent_layer) Then
     renamed_layer = layer_name
   Else
     renamed_layer = parent_layer & separator & layer_name
     Rhino.RenameLayer layer_name, renamed_layer
   End If
 
   ' Get the layer's immediate children
   layer_children = Rhino.LayerChildren(renamed_layer)
   If IsArray(layer_children) Then
     ' Process these layers too    
     ProcessLayerList layer_children, separator
   End If  
 
 End Sub