<P> In about 1413 a contemporary of Ghiberti , Filippo Brunelleschi , demonstrated the geometrical method of perspective , used today by artists , by painting the outlines of various Florentine buildings onto a mirror . When the building 's outline was continued , he noticed that all of the lines converged on the horizon line . According to Vasari , he then set up a demonstration of his painting of the Baptistery in the incomplete doorway of the Duomo . He had the viewer look through a small hole on the back of the painting , facing the Baptistery . He would then set up a mirror , facing the viewer , which reflected his painting . To the viewer , the painting of the Baptistery and the building itself were nearly indistinguishable . </P>
who is often credited as the first painter to fully utilize the theory of linear perspective
Filippo Brunelleschi