perspective, aerial perspective and linear perspective.
The 15th century in Italy
Two possibilities: The line is linear over some of its length and then goes non-linear (or the other way round: Think of a mass, at the end of a string, being swung in a circle. Then the string is cut. The motion of the mass would have been circular (lon-linear) until the instant the string was cut and then linear, as it flies off into a tangent. Or The line is linear from one perspective but not from another: Think of the trajectory of a ball that is thrown up at an angle to the horizon. If seen from above, the ball travels in a straight line (linear) but if seen from the side it follows a parabola (non-linear). Hope that helps.
Linear perspective creates the illusion of depth on a flat canvas by using converging lines that draw the viewer's eye toward a vanishing point on the horizon. This technique mimics how parallel lines appear to converge in the distance, allowing artists to depict objects at varying distances. By adjusting the size and placement of shapes relative to this perspective, artists can create a realistic sense of space and volume, making the two-dimensional surface appear three-dimensional. Additionally, the use of overlapping elements and atmospheric perspective further enhances this illusion.
In linear perspective there is a horizon line and a vanishing point to which all non horizontal lines lead to. There are also vertical lines. Proportion lines are simply a starting point for an artist to determine the correct proportions of the portrait or picture.
above the objects in a painting.
above the objects in a painting.
above the objects in a painting.
above the objects in a painting.
Establish a horizon line and a vanishing point
linear perspective
Many paintings offer an illustration of both atmospheric and linear perspective, I would recommend Looking at Claude Lorrain's 1648 oil painting "Embarkation of the Queen of Sheba". Linear perspective can be seen by the straight lines which angle in towards the sun on the horizon. Atmospheric perspective can be seen by the way the closest building is detailed and the farther buildings have less detail.
linear perspective
It is believed that the first painter to use linear perspective was Polygonus, in 5th Century BC Greece. We cannot be certain because Greeks painted only on wooden boards, none of which survive. The first modern painting to depict linear perspective was Masaccio's "The Tribute Money" which was done in Florence, Italy in the early 15th Century. It depicts a new testament story.
linear perspective :)
An early attempt at perspective (apex)
linear perspective