问Sketchup动态组件的错误位置和距离

EN

def self.definition(instance)
    if instance.is_a?(Sketchup::ComponentInstance)
    # ComponentInstance
    return instance.definition
    elsif instance.is_a?(Sketchup::Group)   
      if instance.entities.parent.instances.include?(instance)
          return instance.entities.parent
      else
          Sketchup.active_model.definitions.each { |definition|
          return definition if definition.instances.include?(instance)
          }
      end
    elsif instance.is_a?(Sketchup::Image)
    Sketchup.active_model.definitions.each { |definition|
        return definition if definition.image? && definition.instances.include?(instance)
    }
    end
    return nil # Error. We should never exit here.
end

mod = Sketchup.active_model # Open model
ent = mod.entities # All entities in model
sel = mod.selection # Current selection
puts ent[0]
faces =  definition(ent[0]).entities.grep(Sketchup::Face)
puts faces
faces[0].material = "Purple"
faces[0].vertices.each {|v| puts v.position}
puts '---'
f0_v = faces[0].vertices
for i in 0..f0_v.size - 2
  puts f0_v[i].position.distance(f0_v[i+1].position)
end
puts f0_v[3].position.distance(f0_v[0].position)

#<Sketchup::Group:0x000001ba478591e0>
#<Sketchup::Face:0x000001ba4810ca58>
#<Sketchup::Face:0x000001ba4810c828>
#<Sketchup::Face:0x000001ba4810c350>
#<Sketchup::Face:0x000001ba4810c2d8>
#<Sketchup::Face:0x000001ba4810c1e8>
#<Sketchup::Face:0x000001ba4810c1c0>
(0 mm, 0 mm, 300 mm)
(0 mm, 0 mm, 0 mm)
(300 mm, 0 mm, 0 mm)
(300 mm, 0 mm, 300 mm)
---
300 mm
300 mm
300 mm
300 mm