1, 2, & 3 Point Linear Perspective
You can imply perspective by the relative size of objects, layering foreground, mid-ground, and background elements, changing focus by sharpening or softening details, and lightening or darkening elements as the atmosphere changes the quality of “seeing” things in the distance.
If you can combine linear perspective with natural perspective, you can make a convincing drawing that easily allows the observer to “suspend belief” and be drawn into your creation.
(1) One Point Perspective
(Single Point - One Vanishing Point)
The front plane of the object is directly in front of you, verticals parallel, and all lines of perspective meet at a single vanishing point on the horizon. Objects you draw in one point perspective are drawn face on.
Practice: 1) Draw a horizon line and center a vanishing point. 2) Draw a square or rectangle off to the side of the vanishing point, overlapping the horizon line. 3) Lightly draw (or visualize) orthogonal "visual rays" from the vanishing point through the edges of your object. 4) Then draw the vertical lines of the back of the object using the rays as a measure.
(Two Vanishing Points)
(2) Two Point Perspective
When an object or viewpoint is rotated and two sides of an object are angled away from your view, each side of the object has it's own unique lines of perspective. You now must use two vanishing points, one for each plane of the surface in view with the vertical lines parallel.
Practice: 1) Draw a horizon line and place two vanishing points on the far right and left sides. 2) Draw a vertical line indicating the closest edge of the object facing you. 3) Lightly draw (or visualize) orthogonal "visual rays" from each vanishing point to the line of the front edge of your object. 4) Then draw the vertical lines of the left and right edges of the object using the rays as a measure.
(Bird’s Eye, Worm’s Eye - Three Vanishing Points)
(3) Three Point Perspective
If your point of observation is higher or lower a third vanishing point comes into use. Think of looking up at tall skyscrapers and seeing three vertical sides angle to a third vanishing point, far distant, as they reach toward the sky. From the Worm’s Eye view (looking up) the upper vanishing point is called the Zenith. From the Bird’s Eye or Helicopter view (looking down) the lower vanishing point is called the Nadir.
Practice: 1) Draw a horizon line and place two vanishing points on the far right and left sides. 2) Draw a vertical line bisecting the horizon line and place a third vanishing point above (or below) the horizon line. 3) Lightly draw (or visualize) orthogonal "visual rays" from the top vanishing point past the horizon line. 4) Then draw orthogonal lines from the left and right vanishing points and bisect the orthogonal lines from the top vanishing points using the rays as a measure..
(Isometric, Dimetric, & Trimetric)
Fixed Point Perspectives
Isometric, Dimetric, and Trimetric drawings are made for illustrating objects to convey technical information. They use parallel lines but utilize no vanishing points. They are not used to create realistic 3 dimensional drawings. That doesn’t mean you can’t use them when you need to express a certain feeling in your art.