Complex sentence: For example, the proto-Renaissance painter Giotto brought a new realism to the art of painting by rendering physical space and volume far more convincingly than his Gothic predecessors even though his paintings, like theirs, represented biblical scenes and the lives of the saints.
Split into simpler sentences: For example, the proto-Renaissance painter Giotto brought a new realism to the art of painting by rendering physical space and volume far more convincingly than his Gothic predecessors. His paintings, like theirs, represented biblical scenes and the lives of the saints.