Perspective is a method of representing three-dimensional objects on a two-dimensional surface such as a paper or canvas. Perspective in the graphic arts is an approximate representation, generally on a flat surface (such as paper), of an image as it is seen by the eye.A perspective drawing achieves a sense of depth or third dimensional within the limits of the flat drawing surface. Since the distortion due the depth is also taken into account, a perspective view is visually more accurate than a normal isometric view. If the objects are large in size, the perspective distortion is more apparent. Someone one across the street appears smaller than the person next to us, a person coming at a far away distance appears still smaller and so on. Imagine another situation. You are walking along a big highway where lamp posts are provided on both the sides throughout. Just mentally take a snapshot. Whether all the posts appear equal in size? We know for sure that they are equal. But they appear to be smaller and smaller in size when they are away and away from the viewer. Persons, buildings cars everything appears so. This apparent view is known as "perspective view".
Linear Perspective:
Linear perspective uses mainly the direction of lines converging towards the vanishing points and thereby creating a visual depth of field.
Horizon Line Or Eye Level Line:
It is the line where the sky and the sea level appear to meet. When a person looks straight, this line will be at his eye level irrespective of whether he is tall or short, This line forms the basis for creating a perspective drawing.
Station Point :
This is the point where the viewer's eyes are positioned. Changing this point will change the view of the object.
Picture Plane:
It is simply the plane where we plot the current view of the object. In practical usage, it is the paper on which we draw.
Vanishing Point:
It is an imaginary point at the eye level line, where all the depth lines from objects seem to converge. In parallel perspective, the depth lines converge to a single vanishing point where as in an angular perspective drawing, two vanishing points are in use. In three-point perspective, three vanishing points are employed which offer a dramatic zoom view to the object.
Single Point Perspective :
When a side of an object is facing the viewer the depth lines appears to converge at a point called vanishing point located at the horizon line . Since all the depth lines focus towards a single point, it is known as single point perspective.
Two Point Perspective :
Instead of a side, if the edge of an object is facing the viewer, the depth lines appear to converge at two different points located at the horizon line. Hence this type is known as two point perspective.
Three Point Perspective:
When a corner of an object is facing the viewer, the dimensional lines appear to converge at three different vanishing points. This is known as three-point perspective. Since three point perspective creates a dramatic look, it is widely used in ad & comic panels etc.
Aerial Perspective :
Aerial perspective is creating a sense of depth in an artwork by imitating the way the atmosphere makes distant objects appear less distinct and more bluish than the nearby objects. Also known as atmospheric perspective. This type of perspective is achieved by treating detailing of the objects of fore ground, middle ground and background differently.
