Some of the greatest artists of the Renaissance competed to make these doors. It is ironic that the man who finally developed the solution to the engineering problem posed by the dome lost this contest. It is said that the panels submitted by both Ghiberti and Brunelleschi represented a dramatic change from the flat, dehumanized work that typified relief sculptures of the time. They had incorporated the developing concepts of perspective and humanism into their art. Ghiberti took 21 years to complete the doors that depict significant passages from the Old Testament. They are now stored in the Museo dell'Opera del Duomo. Replicas on the baptistry draw viewers from around the world.