For an artist working in the 15th century, some study of the nature of light was essential. It was by the effective painting of light falling on a surface that modelling.
In the early 16th century maps were rare and often inaccurate. Leonardo produced several accurate maps such as the town plan of Imola created in order to win the patronage.
As Leonardo became successful as an artist, he was given permission to dissect human corpses at the hospital Santa Maria Nuova in Florence. Later he dissected in Milan at the hospital.
Leonardo began the formal study of the topographical anatomy of the human body when apprenticed to Verrocchio. He would have been taught to draw the human body.
Leonardo illustrated a book on mathematical proportion in art written by his close friend Luca Pacioli and called De divina proportione, published in 1509.
Leonardo kept a series of journals in which he wrote almost daily, as well as separate notes and sheets of observations, comments and plans. He wrote and drew with his left hand.