Convergence behavior of lines parallel to the picture plane In perspective, sets of lines that are parallel to the picture plane remain parallel in the image and do not converge toward any vanishing point.

Introduction / Context:
Vanishing points arise in perspective when sets of spatially parallel lines are not parallel to the picture plane; they intersect the picture plane at finite points and appear to converge. Understanding which directions converge and which remain parallel helps drafters set up one-, two-, or three-point constructions correctly.

Given Data / Assumptions:

• We are working with standard linear perspective.
• A set of lines is parallel to the picture plane (not merely coplanar with some other plane).
• We observe their image on the picture plane.

Concept / Approach:
If a family of lines is parallel to the picture plane, their directions have no component receding away from the plane. Projection rays from the station point intersect these lines without inclination into depth; thus their images remain parallel and do not meet at a vanishing point. Only directions that angle into or out of the plane generate convergence to finite vanishing points.

Step-by-Step Solution:

Verification / Alternative check:
Construct two-point perspective of a box: the verticals and horizontals parallel to the picture plane remain parallel; only edges receding to left/right converge to their respective vanishing points.

Why Other Options Are Wrong:
Limiting the statement to verticals, eye level, or one-point perspective is unnecessary; the criterion is geometric alignment with the picture plane in any perspective setup.

Common Pitfalls:
Confusing “in the picture plane” with “parallel to it,” misplacing the horizon line, or assuming all parallels always converge.

Final Answer:
Correct