When the term "Renaissance" is applied, especially in art, "Realism" is not the first component that comes to mind. But Renaissance art was just that -- a movement that emphasized what is real. No more impressions. No more rearranged parts. No more artistic perspective.
Renaissance artists studied and painted light, shadow, detail, and lines. It was during the High Renaissance in Italy (1475-1525) that Leonardo da Vinci introduced the study of anatomy and made it an art.