Illusionistic ceiling painting, which includes the techniques of perspective di sotto in sù and quadratura, is the tradition in Renaissance, Baroque and Rococo art in which trompe-l'œil, perspective tools such as foreshortening, and other spatial effects are used to create the illusion of three-dimensional space on an otherwise two-dimensional or mostly flat ceiling surface above the viewer. It is frequently used to create the illusion of an open sky, such as with the oculus in Andrea Mantegna's Camera degli Sposi, or the illusion of an architectural space such as the cupola, one of Andrea Pozzo's frescoes in Sant'Ignazio, Rome. Illusionistic ceiling painting belongs to the general class of illusionism in art, designed to create accurate representations of reality. Di sotto in sù Di sotto in sù (or sotto in su), which means "seen from below" or "from below, upward" in Italian, developed in late quattrocento Italian Renaissance painting, notably in Andrea Mantegna's Camera degli Sposi in Mantua and in frescoes by Melozzo da Forlì. Italian terminology for this technique reflects the latter artist's influence and is called prospettiva melozziana ("Melozzo's perspective"). Another notable use is by Antonio da Correggio in the Parma Cathedral, which foreshadows Baroque architecture grandeur. The technique often uses foreshortened figures and an architectural vanishing point to create the perception of true space on a painted, most often frescoed, ceiling above the viewer. Quadratura Quadratura, a term which was introduced in the seventeenth century and is also normally used in English, became popular with Baroque artists. Although it can also refer to the "opening up" of walls through architectural illusion, the term is most commonly associated with Italian ceiling painting. Unlike other trompe-l'œil techniques or precedent di sotto in sù ceiling decorations, which often rely on intuitive artistic approaches to deception, quadratura is directly tied to seventeenth-century theories of perspective and the representation of architectural space. Due to its reliance on perspective theory, it more fully unites architecture, painting and sculpture and gives a more overwhelming impression of illusionism than earlier examples. The artist would paint a feigned architecture in perspective on a flat or barrel-vaulted ceiling in such a way that it seems to continue the existing architecture. The perspective of this illusion is centered towards one focal point. The steep foreshortening of the figures, the painted walls and pillars, creates an illusion of deep recession, heavenly sphere or even an open sky. Paintings on ceilings