Horizon placement rule: Should the horizon line in a perspective view be drawn at a height above the ground line equal to the station point (eye) height above the ground plane?

Introduction / Context:
The horizon line (HL) represents eye level in perspective drawings and greatly influences composition and vanishing point placement. This question asks whether the HL height above the ground line equals the station point height above the ground plane.

Given Data / Assumptions:

• Station point (SP) has a defined elevation relative to the ground plane.
• Ground line (GL) is the intersection of the ground plane with the picture plane.
• Horizon line corresponds to eye level, independent of the specific object geometry.

Concept / Approach:
By construction, the HL is located at the vertical position on the picture plane that corresponds to the observer’s eye level. If the SP is 1.6 m above the ground plane, the HL is drawn 1.6 m above the GL (to scale in the drawing). Thus, HL height equals SP elevation relative to the ground plane.

Step-by-Step Solution:
Set SP height relative to ground plane.Project that height onto the picture plane to establish HL.Draw HL parallel to GL at this elevation.Result: HL–GL separation equals SP height.

Verification / Alternative check:
Visual intuition: as the observer’s eye rises, the horizon rises in the image; when eye level is at ground height, HL coincides with GL.

Why Other Options Are Wrong:
The rule is general; it is not restricted to two-point views, vertical PP requirements, or outdoor scenes.

Common Pitfalls:
Confusing horizon with skyline; the HL is geometric eye level, not the silhouette of distant terrain.

Final Answer:
Correct