Both magicians and artists entertain with illusions. While the magician uses smoke, mirrors and other props, the artist must rely on a flat two-dimensional surface to imply an illusion of visual depth and convince the viewer that a scene is three dimensional. One of the ways visual depth can be expressed is through linear perspective.
Linear perspective conveys depth through lines and the placement of forms. Though compositions may vary in complexity, the following tips and basic principles are inherent to all linear perspective drawings.
Horizon: The horizon is the line where the sky meets the land or water. The height of the horizon will influence the placement of the vanishing points and the elevation of the scene.
Vanishing point: A vanishing point is the place where parallel lines appear to meet in the distance. In the example above, the parallel lines of the road recede or travel backward and visually merge to create a single vanishing point on the horizon. There is no limit to the number of vanishing points that a scene may have.
Ground plane: The ground plane is the horizontal surface below the horizon and may be land or water. In the example above, the ground plane is level. However, if the ground plane were sloped or hilly, the vanishing point, which is created by the path’s parallel lines, would not rest on the horizon and might appear as if it were on an inclined plane.
Orthogonal lines: These are lines that are directed to a vanishing point, such as the parallel lines of railroad tracks shown above. Orthogonal means right angle. It refers to right angles that are formed by lines such as the corner of a cube shown in perspective.
Vantage Point: Not to be confused with vanishing point, the vantage point is the place from which a scene is viewed. The placement of the horizon and the vanishing points will affect the vantage point.
Four principles that characterize how depth is conveyed in linear perspective are size of forms, overlap of forms, placement of forms and convergence of lines. All four principles can and should be used together to best interpret perspective.
Size of Forms: The largest of similar forms will appear closest to the viewer. With this scene, the square on the right appears closest because it is largest of the three. The square on the left appears to be the farthest away because it is the smallest.
Overlap of Forms: The square at the top looks bigger because it is overlapping the square at the bottom.
Placement of Forms: Forms that are placed farthest from the horizon will appear closest to the viewer. The square on the right is farther from the horizon than the other two boxes causing it to look closer to the viewer, whereas the other boxes are closer to the horizon, making them appear more distant.
Convergence of Lines: Parallel lines converge in the distance. In this scene the road lines (orthogonal lines) meet as they recede into the distance, giving the appearance of depth. Where the orthogonal lines meet a vanishing point is formed. The principle of convergence of lines shares the concept of depth expressed through size in that the width of the path decreases with distance.
As you become more familiar with these basic principles of linear perspective, you may find that you were already applying them, but you didn’t realize it. Utilizing these skills is sure to improve the accuracy of your drawings.
Mark and Mary Willenbrink, best-selling authors of the Absolute Beginner art instruction series (North Light Books), have been working together as a team in the publishing industry for decades. Sharing the fundamentals of art in understandable terms, Mark and Mary enjoy encouraging others to pursue their creative potential. Mark is a fine artist and teaches art classes and workshops. Mary is an author and home-school mom. Mark and Mary live with their family, border collie and two cats in southwestern Ohio.