Mine

class V3	attr_accessor :x	attr_accessor :y	attr_accessor :z		def initialize( x, y, z )		self.x = x		self.y = y		self.z = z	end	def +( v3 )		V3.new( self.x+v3.x, self.y+v3.y, self.z+v3.z )	end	def to_s()		"#{x},#{y},#{z}"	endendclass Node	attr_accessor :ruleId	attr_accessor :parent	attr_accessor :position	attr_accessor :rotation	attr_accessor :scope	attr_accessor :subNodes	attr_accessor :shapeType	def initialize( ruleId, parent, shapeType, position=nil, rotation=nil, scope=nil )		self.ruleId = ruleId		self.parent = parent		self.position = position		self.rotation = rotation		self.scope = scope		self.shapeType = shapeType		self.subNodes = []	end	def <<( subNode )		self.subNodes << subNode	end	def to_s()		shapeType.to_s() + ":" + ruleId.to_s() + "@(" + position.to_s() + ")(" + scope.to_s() + ")[" + subNodes.to_s() + "]"	endendclass Splitendclass Bottom < Splitendclass Top < Splitendclass SubShape	attr_accessor :shapeType	attr_accessor :position	attr_accessor :rotation	attr_accessor :scope	def initialize( shapeType, position, rotation, scope )		self.shapeType = shapeType		self.position = position		self.rotation = rotation		self.scope = scope	endendclass Shape	def component( splitType, position, rotation, scope )	endendclass Box < Shape	def componentBottom( position, rotation, scope )		SubShape.new( Rectangle, position, rotation, Scope.new(scope.x,scope.y,0) )	end	def component( splitType, position, rotation, scope )		[ componentBottom( position, rotation, scope ) ]	endendclass Cylinder < Shapeendclass Rectangle < Shapeendclass Rule	attr_accessor :id	attr_accessor :condition	attr_accessor :generativeParts	attr_accessor :probability	def initialize( id, generativeParts, probability=1 )		self.id = id		self.generativeParts = generativeParts		self.probability = probability	end	def apply( node )		generate( node, self.generativeParts, node.position, node.rotation, node.scope )	end	def generate( node, generativeParts, position, rotation, scope )		returns = []		generativeParts.each { |generativePart|			if generativePart.is_a?(ContextEdit) then				(position, rotation, scope) = generativePart.apply( position, rotation, scope )			elsif generativePart.is_a?(Instantiate) then				returns << generativePart.apply( position, rotation, scope )			elsif generativePart.is_a?(SubContext) then				returns.concat( generate( node, generativePart.generativeParts, position, rotation, scope ) )			elsif generativePart.is_a?(Component) then				returns.concat( generativePart.apply( node.shapeType, position, rotation, scope ) )			end		}		return returns	endendclass GenerativePart	def apply()	endendclass SubContext < GenerativePart	attr_accessor :generativeParts	def initialize( generativeParts )		self.generativeParts = generativeParts	endendclass ContextEdit < GenerativePart	attr_accessor :v3	def initialize( v3 )		self.v3 = v3	end	def apply( position, rotation, scope )		[ position, rotation, scope ]	endendclass Translation < ContextEdit	def apply( position, rotation, scope )		[ position+v3, rotation, scope ]	endendclass Rotation < ContextEdit	def apply( position, rotation, scope )		[ position, rotation+v3, scope ]	endendclass Scope < ContextEdit	def apply( position, rotation, scope )		[ position, rotation, v3 ]	endendclass Component < GenerativePart	attr_accessor :splitType	attr_accessor :ids		def initialize( splitType, ids )		self.splitType = splitType		self.ids = ids	end		def apply( shapeType, position, rotation, scope )		subNode = []		shapeType.component( splitType, position, rotation, scope ).each{ |subShape|			if ids != [] then				id = ids.shift()			end			subNode << Node.new( id, nil, subShape.shapeType, subshape.position, subShape.rotation, subShape.scope )		}	endendclass Instantiate < GenerativePart	attr_accessor :shapeType	attr_accessor :id	def initialize( shapeType, id )		self.shapeType = shapeType		self.id = id	end	def apply( position, rotation, scope )		Node.new( id, nil, shapeType, position, rotation, scope )	endendclass RulesSet	attr_accessor :rules	def initialize()		self.rules = []	end	def <<(rule)		self.rules << rule	end	def apply( node )		self.rules.each{ |rule|			if rule.id == node.ruleId then				node.subNodes = rule.apply( node )				node.subNodes.each{ |subNode|					apply( subNode )				}				break			end		}		return node	endendrulesSet = RulesSet.new()rulesSet << Rule.new( "root", [Scope.new(V3.new(2,2,2)), SubContext.new([Translation.new(V3.new(1,1,0)), Instantiate.new(Cylinder,"b")]), Instantiate.new(Cylinder,"b")] )rulesSet << Rule.new( "b", [Scope.new(V3.new(1,1,1)), Instantiate.new(Box,"c")] )rulesSet << Rule.new( "c", [Component.new(Bottom,nil)] )root = Node.new( "root", nil, Box, V3.new(0,0,0), V3.new(0,0,0), V3.new(5,5,3) )tree = rulesSet.apply( root )print tree.to_s() + "\n"