[WIP] CleverClay - Need help

[Pixero]

I'm writing a script to change all materials to gray but leave transparency if any.
It works on non grouped geometry.
How to make it work on Grouped geometry as well?

# CleverClay.rb
# Version; 1.0
# Turns all materials Gray but keeps transparency if any
# Jan Sandström www.pixero.com
# Based on Thomthoms "Blackout"

require 'sketchup.rb'

#-----------------------------------------------------------------------
is_this_file=File.basename(__FILE__)
if not file_loaded?(is_this_file)
  UI.menu("Plugins").add_item("JS Clever Clay"){claymaker}
end
#-----------------------------------------------------------------------
file_loaded(is_this_file)

	def claymaker
		# Make use of the SU7 speed boost with start_operation while making sure it works in SU6.
		if Sketchup.version.split('.')[0].to_i >= 7
			Sketchup.active_model.start_operation("claymaker", true)
		else
			Sketchup.active_model.start_operation("claymaker")
		end
		
			model = Sketchup.active_model 
			materials = model.materials
			entities = model.entities
			
			m = materials.add "ClayMat" 
			m.color = [200, 200, 200]
			m.alpha = 1

		entities.each { | e |
			if (e.material == nil) && (e.kind_of?(Sketchup;;Face))
				e.material = "ClayMat"
				e.back_material = "ClayMat" if e.respond_to? "back_material"
			end
			if (e.kind_of?(Sketchup;;Face) && (e.material.alpha < 1 )) 
				e.material.texture = nil
				e.material.color = [200, 200, 200]
			end
			if (e.kind_of?(Sketchup;;Face) && (e.material.alpha == 1 )) 
				e.material = "ClayMat"
				e.back_material = "ClayMat" if e.respond_to? "back_material"
			end
		}
		Sketchup.active_model.commit_operation
	end

[thomthom]

    # CleverClay.rb
    # Version; 1.0
    # Turns all materials Gray but keeps transparency if any
    # Jan Sandström www.pixero.com
    # Based on Thomthoms "Blackout"

    require 'sketchup.rb'

    #-----------------------------------------------------------------------
    is_this_file=File.basename(__FILE__)
    if not file_loaded?(is_this_file)
      UI.menu("Plugins").add_item("JS Clever Clay"){claymaker}
    end
    #-----------------------------------------------------------------------
    file_loaded(is_this_file)

       def claymaker
          # Make use of the SU7 speed boost with start_operation while making sure it works in SU6.
          if Sketchup.version.split('.')[0].to_i >= 7
             Sketchup.active_model.start_operation("claymaker", true)
          else
             Sketchup.active_model.start_operation("claymaker")
          end
          
             model = Sketchup.active_model
             materials = model.materials
             entities = model.entities
             
             m = materials.add "ClayMat"
             m.color = [200, 200, 200]
             m.alpha = 1

          entities.each { | e |
             if (e.material == nil) && (e.kind_of?(Sketchup;;Face))
                e.material = "ClayMat"
                e.back_material = "ClayMat" if e.respond_to? "back_material"
             end
             if (e.kind_of?(Sketchup;;Face) && (e.material.alpha < 1 ))
                e.material.texture = nil
                e.material.color = [200, 200, 200]
             end
             if (e.kind_of?(Sketchup;;Face) && (e.material.alpha == 1 ))
                e.material = "ClayMat"
                e.back_material = "ClayMat" if e.respond_to? "back_material"
             end
          }
		  
		  # Loop over all the definitions in the model
		  model.definitions.each { |d|
			d.entities.each { |e|
				# do the same stuff you did to the model.entities here.
			}
		  }
		  
		  
          Sketchup.active_model.commit_operation
       end

[Pixero]

Thanks!