How did painted ceilings in Baroque churches create an illusion of heaven?

Baroque church ceilings created an illusion of heaven by dissolving architectural boundaries through the use of illusionistic painting and dramatic sensory effects. By integrating painting, sculpture, and architecture into a unified decorative ensemble, artists sought to direct the worshiper’s focus toward heavenly concerns.12

Key techniques used to achieve this effect included:

• Sotto in su: This technique involves extreme foreshortening of figures painted on high surfaces, creating the convincing illusion that saints and angels are suspended in the air above the viewer.32
• Dissolving Frames: Baroque frescoes often "burst out" of their frames, with painted figures appearing to spill over architectural moldings and stucco decorations into the actual space of the church.4
• Dynamic Composition: Unlike the stable, symmetrical space of the Renaissance, Baroque ceilings utilized complex, diagonal compositions filled with figures possessing superabundant vitality, which helped create a sense of infinite, dynamic space.12
• Sensory Appeal: Through the use of vivid colors, dramatic light and shade, and lavish highlights, these paintings made the religious experience immediate and emotionally resonant, serving as a powerful tool for the Counter-Reformation to stimulate piety.24