Perspective and spatial representation
Domain 4 - Perspective and spatial representation. The exam tests whether you can construct believable depth using eye level, vanishing points and foreshortening, and whether you can explain why a drawing looks spatially correct.
Core rules
- Eye level = horizon line. Every vanishing point for horizontal receding edges lies on this line. The station point is the viewer's position; it controls the cone of vision but is rarely drawn.
- One-point perspective: the front face of a box or room is parallel to the picture plane; one set of edges recedes to a single vanishing point. Use it for frontal interiors, corridors and street views.
- Two-point perspective: the nearest edge is a vertical; two sets of horizontal edges recede to left and right vanishing points on the horizon. Verticals stay vertical when the picture plane is upright.
- Height and position: objects below eye level show their tops; objects above show their undersides. Measure heights from the ground line, not from the horizon.
- Foreshortening: forms pointing towards the viewer shorten; use overlapping, size change, ellipse curvature, reduced detail and convergence. A forearm aimed at you becomes a short cylinder with a large hand.
Worked example
A rectangular box below eye level in two-point perspective. Draw the horizon at 1.5 m, place the nearest vertical, then send its top and bottom edges to left and right vanishing points on the horizon. Because the box is below eye level, the top face is visible. The front vertical is the tallest; receding verticals diminish as they approach the vanishing points. Reasoning: one horizon controls both vanishing points, and the box's position relative to eye level explains which faces are seen.
Traps
Two different horizons in one drawing; vanishing points not on the horizon; parallel receding edges that never converge; drawing the top of a box that is above eye level; measuring height from the horizon; foreshortened limbs drawn at full length; calling any diagonal a perspective line.