Da Vinci's Suumato Technique

The Baptism of Christ was painted by Baroquio and Da Vinci together. The technique in this painting was so ahead of its time that supposedly after the baptism of Christ, Baroquio vows never to paint again. Now why was Leonardo so focused on these new techniques? He wrote that the first intention of the painter was to make a flat surface display a body as if modeled and separated from this plane. Both Da Vinci and Pixar were consumed with the same problem with how to render three dimensional objects on a two dimensional surface.