What Renaissance painting technique creates the illusion of depth?

Answer 1

Several things contribute to this. Perspective (things in foreground are larger. Also, horizontal lines angle down to the vanishing point), Shading ( things farther back look grayer, making the outlines of distant objects fuzzier). Certain colors tend to "come forward" and others recede.

Answer 2

Perspective.

The technique artists use to project an illusion of the three-dimensional world onto a two-dimensional surface. Perspective helps to create a sense of depth — of receding space. Fundamental techniques used to achieve perspective are: controlling variation between sizes of depicted subjects, overlapping some of them, and placing those that are on the depicted ground as lower when nearer and higher when deeper. In addition, there are three major types of perspective: aerial perspective, herringbone perspective, and linear perspective

Answer 3

Chiarscurro was the use of light to dark - adding depth to paintings. DaVinci was a master of it.