The class is somewhat like a module in this context... But still best to include the whole lot inside your own module... Can I suggest you revisit your various entities definitions. Sometimes you use model.active_entities, another model.entities, they might not always be the same thing... Also if you make your group and immediately add thing to group.entities it might be easier...

This is what I use # Let 'point' be the new insertion point of the component. # Let vector=ORIGIN.point.vector_to(point) # Let tr=Geom;;Transformation.translation(vector) vector = component.transformation.origin.vector_to(new_origin) tr = Geom;;Transformation.translation(vector) component.definition.entities.transform_entities(tr.inverse, component.definition.entities.to_a) # All of the component's innards jump to suit, so the instance is now in the wrong place relative to its container's contents... # To fix any instances so the contents are placed back as they were, inside their individual container... component.definition.instances.each{ |inst| inst.transform!(tr) } component.definition.invalidate_bounds