What is the defining characteristic of three-point perspective?

Three-point perspective is characterized by the use of three vanishing points, which are typically positioned at two points along the horizon line and one point either above or below it. This technique is particularly effective for depicting objects at an angle or when looking up or down at tall structures. The vanishing point above or below the horizon line helps to create a sense of depth and realism, making it easier for the viewer to understand spatial relationships within the composition.

The other options don't accurately convey the defining aspects of three-point perspective. For instance, the rule of thirds is a compositional guideline that aids in placing subjects within an artwork, but it doesn't relate specifically to the mechanics of perspective. True shape maintenance pertains more to parallel projections like orthographic drawing rather than perspective techniques. Lastly, while balance is important in art, three-point perspective does not inherently require a central axis; it is focused more on the spatial relationships created by the vanishing points.