Since prehistoric times mankind depicted three dimensional natures on a flat surface. Here are the drawings by a Stone Age artist done 32,000 years ago. This is the oldest art known to man. It was discovered in a cave located in Southern France.

ARCHITECTURAL GRAPHICS -II University of Kerala

Module – I

7/10/2014

SAMBATH.RD

13AR1305 ARCHITECTURAL GRAPHICS -II Module – I

Perspective drawing

Leonardo’s window

Perspective projection concepts.

Vanishing points.

Station points.

Picture planes.

Types of perspective-

Single point perspective,

Two point perspective.

Perspective projection of simple objects, buildings,

Interior perspectives, human figures.

Landscapes etc in perspective, Sciography.

Figure 1

What are the main rules of perspective?

The rules are quite simple and can be seen in our everyday experience. The objects closer to a viewer appear bigger than similar objects located further away.

The objects on a foreground will partially or completely cover objects on the background if they are aligned on the same ray (line) of view.

The further away objects are, the less detailed they look and the less contrasting and saturated their colors become.

History of drawing in perspective

Since prehistoric times mankind depicted three dimensional natures on a flat surface. Here are the drawings by a Stone Age artist done 32,000 years ago. This is the oldest art known to man. It was discovered in a cave located in Southern France.

The cave wall murals portray various animals using extraordinary expressive drawing techniques. The ‘panel of horses’ has use of perspective, which shows several animals on the same plane. Similar perspective is applied for lions, rhinos and other animals. The animals that are closer to the viewer are bigger in scale and partially cover the animal behind.

Similar perspective can be found in ancient Egypt frescoes and drawings. Human figures are arranged in planes and the modern viewer has no are further away. In Egyptian art, the difficulties to understand which figures are closer and which scale of figures does not always follow the rules of perspective as characters’ size often corresponds to their social hierarchy.

Egyptians artists often arranged drawing compositions in horizontal bands, which gave clear representation of different fields of view – foreground, middle-ground, and background.

Figure 4

Figure 2

Figure 3

This parallel perspective is used in combination with one-point perspective, where two edges of his support will eventually meet in one point.

Figure 5

Here’s the fresco by Raphael “The Athens School”. The main vanishing point of this composition is located on the hand of Plato; however, the background has the lower horizon line. At the same time, the group of people, surrounding Plato, is drawn in parallel perspective, while Plato’s support has clear one-point perspective.

One-, two-, and three-point perspective found a new life during the Renaissance time. Understanding rules of linear perspective helped fine artists depicting the world in a realistic

manner. However, many of them realized that following linear perspective to the point gives unwanted

distortions and often corrected such distortions by introducing multiple vanishing points on various levels

These rules were known to fine artists for many centuries. Here’s what Leonardo da Vinci said about perspective:

“There are three aspects to perspective.

The first has to do with how the size of objects seems to diminish according to distance:

the second, the manner in which colors change the farther away they are from the eye;

The third defines how objects ought to be finished less carefully the farther away they are.

During the Renaissance, European artists began to study the model of nature more closely and to paint with the goal of greater realism. They learned to create lifelike people and animals, and they became skilled at creating the illusion of depth and distance on flat walls and canvases by using the techniques of linear perspective.

Figure 6

Figure 7

During the Renaissance in Italy, architects and artists investigated the question of how to draw three dimensional objects on flat surfaces.

They began to think of a painting as an "open window" through which the viewer sees the painted world.

They also developed a system of mathematical rules known as linear perspective to help painters achieve their goal of realism.

To use linear perspective an artist must first imagine the picture surface as an "open window" through which to see the painted world.

Straight lines are then drawn on the canvas to represent the horizon and "visual rays" connecting the viewer's eye to a point in the distance.

The horizon line runs across the canvas at the eye level of the viewer. The horizon line is where the sky appears to meet the ground.

Figure 8

Figure 9 .

In painting the Virgin of the Rocks, Leonardo applied his understanding of aerial perspective to create the sense of mountains a great distance away.

Leonardo was fascinated by the atmosphere and by its effects on the colors and distinctness of distant objects. Though other artists had already begun to create some of these effects in their work, Leonardo was the first to make careful measurements and suggest rules for applying them realistically in painting. He called the subject Aerial perspective. In morning light Leonardo observed that distant objects such as mountains look bluer and less distinct than nearby mountains. He also noted that the more distant the mountain, the more its color approached that of the surrounding atmosphere.

His experiments suggested that to correctly color objects at different distances, artists should do as follows: Paint the nearest one its true color. Paint the one behind proportionately bluer, and the one behind that bluer

In this computer generated scene, the colors have been made the same for nearby and distant objects as if there were no atmospheric effects

Perspective Projection

Captures a true three-dimensional view onto a two-dimensional plane.

What is Perspective Projection?

Perspective projection is a form of pictorial drawing that gives the illusion of depth onto a flat surface, very similar to that of viewing of the object through the human eye. In comparison to other types of projection systems, for example orthographic and oblique, the spectator is viewing the object from infinity. The projection rays radiate parallel to each other from the object back to the spectator, compared to perspective projection where the projected rays radiate from the object to a single point at a given distance from the object.

Figure 10

The Spectator

Figure 11 the spectator is the name given to the point in which the object is being viewed from.

Figure 12 the spectator in perspective projection shares many similar characteristics with the human eye. An example of this would be cone of vision. In perspective projection the object is viewed using one eye (a single point).

The best way to obtain the distance for the spectator is to consider the object's location within the cone of vision shown. People tend to see most clearly at the centre of their cone of vision, which is represented by a centre line of vision. This line is the axis of our cone of vision, and generally tends to be a horizontal line. The centre line of vision is perpendicular to the picture plane.

Horizon Line and Vanishing Points

Figure 13

Horizon line is the intersection of the ground plane and a plane in accordance to the spectator’s line of vision.

Vanishing points.

Vanishing points are points that lines and/or surfaces vanish back to in perspective projection. The main principle with vanishing points is that all lines parallel to one or another and receding from the spectator will have their own vanishing point on the

Figure 14

Horizon line. The vanishing points are always located on the horizon line because the horizon

Figure 15

line is the vanishing line of the Earth. Therefore the horizon line can consist of an infinite number of vanishing points.

The Ground Line

This is a straight line on the picture plane that represents the ground. It is important to note that the ground line represents a plane that continues onto the horizon line.

Types of perspective

One Point Perspective.

Two point perspective.

Rules of One Point Perspective

Horizontal lines parallel to the picture plane and remain horizontal.

Vertical lines remain vertical.

Figure 17

The orthogonal lines formed from the corners diverge to the vanishing point. The vanishing point is located in front of the spectator.

How to draw in One Point Perspective

First draw the object. Plan the position of the picture plane and the position of the spectator.

Establish a ground line and the horizon line the same height as the spectator.

Extend lines down from the corner of your plan view to the ground line thus establishing the given object's position.

Figure 16

Connect back the corners of the object to the vanishing point to define its position and shape.

Figure 18

Conditions for Two Point Perspective

For Two Point perspective the object is orientated so that the vertical edges are parallel to the picture plane and all other edges are inclined away from the spectator thus the receding lines converge on two separate vanishing points.

Rules of Two Point Perspective.

To find the vanishing points, lines of sight are drawn parallel to the surfaces of the object until they cross the picture plane.

The object to be viewed is rotated so that all the sides are at an angle to the picture plane.

All vertical lines retract back to their respective vanishing points

Horizontal lines remain horizontal

How to draw in Two Point Perspective

Draw the object plan and establish the orientation of the picture plane in relation to the spectator.

Establish the ground line and horizon line. Draw lines parallel to the side of the object until they strike the picture plane to establish you're VP's.

Join the corner points of the object in plan to the spectator and where the light rays intersect the picture plane, and then project these points to the ground line.

Recede the established edge position in the perspective drawing to their respective vanishing points as shown in the video to the right.

What is Vertical line of measures or measuring line perspective?

Measure line perspective is a mathematical system of making objects relate to each other proportionately. A perspective grid is made to relate to the ground plan; using the grid allows greater ease in measuring distances which

may not correspond to any other scale when the method of foreshortening is put in place. This type of perspective allows a person to transform an in -scale ground plan into a perspective drawing.

Sciography?

Sciography is a branch of science of the perspective dealing with the projection of shadows, or delineation of an object in perspective with its gradations of light and shade. One of the major professional fields that use this technique is the architectural field. In architecture it is defined as a study

of shades and shadows cast by simple architectural forms on plane surfaces.

In general sciography the light source is imagined as the sun inclined at 45 degrees to both vertical plane and horizontal plane coming from left hand side. The resultant shadow is then drawn.

Glossary

Depths of receding surfaces The depth of a receding surface refers to the z-axis of an object, as opposed to the object’s x-axis or y-axis, (i ts width and height). There are two main ways to discover the depth of a receding surface. One way i s to use diagonal l ines with a scale that recedes. The second way is through the use of a scale on the base-line or parallel to i t. The first method is o ften used to free-hand sketch things such as a foreshortened row of fence posts.

Accelerated perspective An intentional exaggeration of perspecti ve often in a stage setting to permit a shallower than appears actual stage depth.

Aerial perspective, atmospheric perspective Often employed in painting, aerial perspective is the way in which an il lusion of space and depth is created through the use of atmospheric techniques. These techniques include making forms in the background region wi th l ess contrast and softer edges than those in

the forefront of the picture plane. Often in atmospheric perspective there exists a change from warmer hues to cool hues. In general, warmer colors come forward, and cooler colors recede (advancing and retreating color). The atmospheric effect in a picture i s due to the degree of moisture suspended in the air. Chinese painters especially employ atmospheric perspecti ve by using clouds or inserting mists in various value tones among the middle areas of the picture plane and introducing fainter tones in the far distance. Aerial perspecti ve is often used together with linear perspecti ve to create a strong sense of spatial depth in the picture. Aerial View Also known as a bird’s eye view. This is the viewpoint seen at a high elevation. It involves the vanishing point/s and horizon line being positioned on the upper portion of an image. It is usually used in reference to a l andscape or a ci tyscape. (Aerial view is not the same thing as aerial perspective.) All-over composition A style of painting in which the entire surface of the piece is worked on in a more or l ess uniform way, and the normal way of treating composition (with the picture having a center, top or bottom) is not considered. The term was originally used in response to Jackson Pollock's drip paintings. Later the term was used to refer to other pieces that refrain from the usual compositional approaches. In this way, the Impressionists "liberated" artists from a decided center of interest - and not necessarily to one of no composition - but rather to mul tiple or all-over points in the picture plane. Angular perspective Angular perspective is a type of l inear perspective. All categories of l inear perspective include a horizon line and a stationary point ( the posi tion of the observer). In two-point perspecti ve, there exist two points from which an object’s l ines radiate from; the sides of the object vanish to one of two vanishing points on the horizon line. An object’s vertical l ines do not relate to the perspective rules of the horizontal l ines. By changing the vanishing points of the object, one can make increase or decrease the size of the object. Angular perspective is the same as two-point perspective. Axis An axi s is a l ine that runs straight through something in order to show the direction and movement of something. The line is purely conceptual – i t is o ften used as a helpful tool for artists. Center vanishing Points CVP The point located on the horizon line that connects to the observation point. Usually i t is at this point where the horizon line and centerline intersect each other. It is also at this point where lines parallel to the picture plane disappear.

Centerline CL

A line, marked as "CL," that is drawn down the middle of a drafting.

Cone of vision The cone of vis ion is the visual region displayed by a drawing that relates to a person’s normal vis ion without his/her peripheral vis ion. In a nutshell, the cone of vision is the area of s ight – or the angle of sight. For example, if a person wanted to see the entire theatre stage, usually a cone of vis ion is 60 degrees is required, so a person would need to sit far enough back to achieve this degree of vision.

Convergence

Convergence in a drawing or painting refers to l inear perspecti ve. In linear perspecti ve,

all l ines that are parallel converge together as they run along to a point at a person’s eye

level (also known as the horizon line) in the picture place. This phenomenon is known as

“convergence.”

Curvilinear perspective

A perspective view in which straight l ines appear to be curved. Close-up and wide angle

views commonly relate to the perspecti ve.

Diminution

Diminution occurs in l inear perspective; i t involves objects becoming smaller and small er

as the space between the viewer and the object increases. Eye Level Eye level refers to the height a viewer’s eyes are positioned in relation to the ground. There are various eye levels. Foreshortening

An il lusion of the eye, creating the ef fect that objects become smaller the further away

they are, and become larger the closer they are to the viewer. Foreshortening is used in

drawing in order to create a sense of depth and make objects appear to exist spatiall y to

each other.

Format

Format relates to the size and shape of a painting. If i t is a rectangle, the orientation

can be longer in the vertical dimension (portrait) - or longer in the horizontal

(l andscape). Format decisions by the artist on both size and shape of the

art surface wil l impact the composi tion strategy and the effects.

Ground line The ground line is the location that a picture plane is posi tioned on the ground. Horizon Line The horizon line is a line drawn across a picture. It is essential for a picture to have a horizon line if a person wishes to communicate from what perspective a person is observing the picture (from above an object, below an object…etc). It is not necessary to include the horizon line in the picture. However, it is important to include a ‘virtual’ horizon line in order to make a picture fo llow correct perspective. The horizon line is always one’s eye level. If one draws a line perpendicular to the ground outwardly from one’s eye level, this is what is considered the horizon line.

Linear Perspective

Linear Perspecti ve relates to the mathematical system of creating objects that are created

three-dimensionally on a two-dimensional surface. It is call ed “linear” perspective

because objects and figures and space are re-created in a realistic manner through the use

of intersecting lines drawn horizontally and vertically. There are three types of l inear

perspecti ve. They include one point perspective, two-point perspective, and three-point

perspecti ve. All of the perspectives include a horizon line and a stationary point ( the

position of the observer). In one point perspecti ve, there is one point that all l ines radiate

from. In two-point perspective, there exist two points from which an object’s l ines radiate

from; the sides of the object vanish to one of two vani shing points on the horizon line. An

object’s vertical l ines do not relate to the perspective rules of the horizontal l ines. By

changing the vanishing points of the object, one can make increase or decrease the size o f

the object. In three-point perspecti ve there are also two vanishing points somewhere on

the horizon; however, unlike two-point perspective, there also exists a vanishing point

above or below the horizon line that the vertical l ines di sappear to.

Measure line perspective Measure line perspective is a mathematical system of making objects relate to each other proportionately. A perspective grid is made to relate to the ground plan; using the grid allows greater ease in measuring distances which may not correspond to any other scale when the method of foreshortening is put in place. This type of perspective allows a person to transform an in-scale ground plan into a perspective.

Oblique perspective Oblique perspective is a type of l inear perspective. All categories of linear perspective include a horizon line and a stationary po int ( the position of the observer). In oblique perspective there are also two vanishing po ints somewhere on the horizon; however, unlike two-point perspective, there also exists a vanishing po int above or below the horizon line that the vertical lines disappear to. Oblique perspective is the same as three-point perspective.

Observation point OP An observation point (OP) i s the single point from which a perspecti ve drawing is looked from. Imagine a ray of l ight radiating from a man's eye upon the scene in front of him - his eye is the observation point. Often the observation point is located on the centerline. One point perspective One-point perspective is a type of l inear perspective. All categories of l inear perspective include a horizon line and a stationary po int ( the position of the observer). In one-point perspective, only one vanishing po int exists; l ines radiate outwardly from this po int, and perpendicular l ines meet at this po int. One-point perspective is the same as parallel perspective.

Orthogonal lines Perspective lines that point to the vanishing point; orthogonal l ines are perpendi cular to one another. Parallel lines Parallel L ines are lines that run in the same direction; they never touch each other because the d istance running between them is always the same. In perspective drawing, lines that are parallel converge in the distance at a vanishing po int.

Parallel perspective Parallel perspective is a type of l inear perspective. All categories of l inear perspective include a horizon line and a stationary point ( the position of the observer). In one-point perspective, only one vanishing po int exists; l ines radiate outwardly from this po int, and perpendicular lines meet at this po int. Parallel perspective is the same as one-point perspective. Perpendicular lines Perpendicular l ines are straight l ines that meet at right angles. The l etter "L" is an example of perpendicular l ines. Perspective grid A grid created mathematically; people use i t as a measuring guide in order to make in-scale perspecti ve drawings. Picture plane A picture plane is the two-dimensional surface upon which a painting/drawing is created. A window can be understood as a picture plane as one looks out to the scene beyond it.

Point of View

A point of view in drawing is simply what position an observer is in relation to the objects in a picture. The point of view is determined by where a viewer is stationed in relation to everything else he sees. For example, if one has a birds-eye view, one will see objects beneath him. If one has a normal view, objects will appear how he normally sees them. If one has a worms-eye view, objects will appear much larger than normal.

Receding parallel lines Receding parallel l ines are lines parallel to each other that gradually move away from the viewer. There are a number of rules that receding parallel lines fo llow in nature. First, all l ines in nature that are parallel to each other appear to converge at the same point as they recede from the viewer. Second, all level lines that recede in nature appear to converge on the horizon. Thirdly, inclining parallel l ines in nature that recede appear to converge at a po int immediately over the point they would have converged IF they had been level l ines. Fourthly, parallel l ines in nature that recede when inclined downward appear to meet at a po int immediately beneath the po int they would have converged had they been level l ines.

Relative Scale Relative scale is a method used to create and determine the spatial position of a f igure or object in 3D picture plane; objects or figures that are more distant are drawn smaller in size than those objects or f igures that are closer to the viewer. And the objects or f igures that are closer are drawn bigger. In this way, the relative size of an object/figure creates the il lusion of space on a f lat 2D picture plane.

Scale (proportion) Scale in drawing refers to the proportion or ratio that def ines the size relationships. Models, architectural plans, maps and paintings/drawings all use scale to create the il lusion of correct size relationships between objects and f igures.

Shallow Space Shallow space refers to a 2D flat space that may have width and density, but contains only a limited amount of depth. For example, a picket fence is an example of an object that demonstrates shallow space because of its lack of depth. Sotto in su In Italian this means "from below upwards." Used in reference to a ceil ing painting wherein the people, f igures, and scenes are depicted foreshortened so that they appear to be suspended in space - and not contained within the f lat structure of the picture plane. Station Point

A station point is used in l inear perspective as a stationary point from which a viewer i s related to the object/figure being rendered. It can be thought of as the point o f reference from which all things in the artwork can be related to. The station point may be very high or very low. High = bird's-eye-view. Low = worm's eye view. It is important to determine the correct station point when starting a piece of work, because the station point has a key role in determining how the viewer understands one’s composi tion and relates to the subject matter. It may also be referred to as "vantage point". Three point perspective

Three-point perspecti ve is a type of l inear perspective. All categories of l inear perspecti ves include a hori zon line and a stationary point ( the posi tion of the observer). In three-point perspective there are also two vanishing points somewhere on the horizon; however, unlike two-point perspective, there also exi sts a vanishing point above or below the horizon line that the vertical l ines disappear to. Three-point perspective is the same as oblique perspective. Two point perspective

Two-point perspective is a type of l inear perspecti ve. All categories of l inear perspecti ve include a horizon line and a stationary point ( the posi tion of the observer). In two-point perspecti ve, there exist two points from which an object’s l ines radiate from; the sides of the object vanish to one of two vanishing points on the horizon line. An object’s vertical l ines do not relate to the perspective rules of the horizontal l ines. By changing the

vanishing points of the object, one can make increase or decrease the size of the object. Two-point perspecti ve is the same as angular perspective. Value

Artists' term for scaling of a composition's l ightness with degrees of gray between endpoints of black and whi te. Colors can also be assessed in the same way for value. Darker relates to "lower" in values. In science, value is "l ightness". Vanishing Point

A point that receding parallel l ines appear to converge to. It is used in l inear perspecti ve in relation to a stationary point ( the placement of the observer). Objects seem to disappear at the vanishing point. Vantage point

A vantage point is used in l inear perspective as a stationary point f rom which a viewer is related to the object/figure being rendered. It can be thought of as the point o f reference from which all things in the artwork can be related to. The vantage point may be very high or very low. High = bird's-eye-view. Low = worm's eye view. It is important to determine the correct station point when starting a piece of work, because the vantage point has a key role in determining how the viewer understands one’s composi tion and relates to the subject matter. It may also be referred to as "station point". Worm's-eye view

A drawing or painting scene that is seen as though the observer is looking up from a position below i t. Properly used i t relies on the oblique perspective. All vertical l ines will converge upward and be parall el to the picture plane. Zero point perspective

Zero-point perspective is a type of l inear perspective. All of types of l inear perspectives include a horizon line and a stationary po int ( the position of the observer). In zero-po int perspective, no vanishing po ints exist; as a result, the image contains no depth.

Zones of recession

The area of a picture’s surface is apportioned to a foreground, a middle distance, and a background when constructing spatial depth. Variations and hazing of these respective zones influence degree of reduction and severity of contrast in the linear perspective. ----------------------------------------------…----------------------------------------------

“Best wishes to my all students. May god shower his bless on my kids to achieve their goals.” -Sambath. Presented by Sambath RD MFA (Broadcast Journalism and Video Production), Master in Media Business Management UGC.NET in Visual Arts. Asst. Professor. Architectural Graphics Department of Architecture T.K.M COLLEGE OF ENGINNERING.