An examination of the drawings for the Fantastic City project from the 1960s shows that Fogliati wanted to build a Temple of light: this would be an indoor environment in which sunlight could be collected and manipulated to create a three-dimensional light sculpture or photostructure.

Fotostruttura reproduces this idea on an exhibition scale; it consists of a horizontal white aluminium disc (with a diameter of about 20 cm) connected to a mechanical structure that makes the disc oscillate vertically over a distance of about 10 cm.

Since the high speed of the oscillation prevents the eye from following the alternating movement, the illusion of a transparent cylinder is created (base 20 cm, height 10 cm.). A luminous image is projected from above on this oscillating “screen”, which reflects the image in every point of the space covered by the alternating vertical movement. In this way, the image is developed three-dimensionally inside the transparent, immaterial cylinder, creating a three-dimensional light sculpture suspended in mid-air (the Fotostruttura).
...

http://www.pierofogliati.it/fotostruttura/?lang=en (30.08.2022)