The Perspective: (4) CIRCLES, ELLIPSES & HORIZON LINES

In this fourth part of our perspective guide, we learn how to draw circles and ellipses in perspective, discover the false horizon line, and understand the horizon line of objects. These concepts are essential for realistic drawing of rounded forms and complex scenes.

Circles and Ellipses

Drawing an ellipse on your sheet amounts to drawing a circle or an ellipse from real life.

Attention, this means directly that we represent a two-dimensional figure from space by a two-dimensional figure on the plane. The consequence is that the “center” of the ellipse (intersection point of the major axis and the minor axis of the ellipse) is not confused with the center of the circle it represents.

To construct the ellipse, we reproduce in perspective the passage points of a circle seen from the front:

The passage point is in reality slightly offset compared to the point that was constructed.

The 4 other passage points are constructed thanks to the vanishing lines.

The False Line of Vision

Attention, it sometimes happens that one has the impression of having discovered the horizon line when it is not the case. This occurs when looking at an inclined plane (a roof, a road that goes up or down, a staircase ramp).

In such cases, the vanishing point found cannot be located on the horizon line since this line only carries the vanishing points of cubes parallel to the ground.

Let’s now observe this church. One can have the impression that it is slightly seen in counter-plunge.

In reality, the view is with two vanishing points and the horizon and vision lines are confused.

If one marks the edges of the alley, one obtains a vanishing point located below the horizon line. We conclude that the alley is in fact descending toward the church.

The Horizon Line of Objects

In reality, what we have just seen are horizon lines of objects.

Every cube parallel to the ground has its horizon line that coincides with the observer’s horizon line and we only retain the latter. On the other hand, if the cube is inclined in relation to the ground, it has its own horizon line, more or less independent of the observer’s horizon line… depending on the type of inclination of the cube.

For a cube parallel to the ground (here in 2 vanishing points), the horizon lines of the observer and of the object are confused.

On the other hand, if the blue line serves as axis of rotation, the right vanishing point will remain unchanged, as will the observer’s horizon line, but the left vanishing point will move and “drag” with it the horizon line of the object.

Next in the series: Dividing space + observation exercises on photos.