Terminology of perspective setup In perspective drawing, the position of the observer’s eye (from which projection rays originate) is called the station point.

Introduction / Context:
Establishing a perspective drawing requires defining the geometric relationship between the observer and the scene. Key constructs include the station point, picture plane, ground line, horizon line, and vanishing points. Using correct terminology ensures consistent communication and accurate construction.

Given Data / Assumptions:

• A single-eye viewpoint is assumed (central projection).
• Projection rays are drawn from that viewpoint to the picture plane.
• Standard one-, two-, or three-point perspective methods are applicable.

Concept / Approach:
The station point is the 3D location of the observer. Rays from the station point intersect the picture plane to form the perspective image. Vanishing points are directions where sets of parallel lines in space appear to meet; they lie on the horizon line (for horizontals) or elsewhere depending on the axis orientation. The picture plane is the “canvas” onto which the projection falls.

Step-by-Step Solution:

Verification / Alternative check:
Verify that moving the station point changes the apparent size and convergence, consistent with visual experience—confirming that the eye position is indeed the projection origin.

Why Other Options Are Wrong:
Vanishing point, picture plane, and horizon point are distinct elements; none describe the observer’s position. They are geometric constructs within or on the projection plane, not the eye location.

Common Pitfalls:
Conflating vanishing points (directions) with the physical viewpoint, or misplacing the station point so near that extreme distortion occurs.

Final Answer:
Correct