Fra Angelico in his works applies a new principle of creating perspectives. Its essence lies in the fact that the figures decrease as they move away from the viewer, and all lines converge to one point on the horizon. Subsequently, this principle has become one of the cornerstones of Renaissance painting. First proposed by his contemporary Fra Angelico, Masaccio, but Fra Angelico reacted to this quite creatively, greatly modernizing it. So, he first resorted to the exploitation of architectural details, exacerbating the sensation of three-dimensional space.
Creating, for example, “The Altar of San Marco”, 1438-40, Fra Angelico places the throne of the Virgin in such a way that he forms the top of the triangle, whose sides are diminishing in the long run rows of figures. To deepen the space of the picture, the geometric pattern of the carpet located in the foreground, and the line of cypresses against the sky, diminish as the distance from the viewer decreases. In the scenes of the perdule of the Perugia triptych, Saint Nicholas towers above the people who hear him preach, while the city houses gradually diminish, creating the illusion of a deep space.