In order to represent a 3-dimensional shape in a 2-dimensional plane, use perspective.

 

The cavalier perspective (Group B: Olivia, Coraline, Steven , Mathilde, Moreen)  
 

What is perspective?
Give perspectives it’s give an aspect of volume of a plane representation.

There are many forms of perspectives : one point perspective , two points perspectives , three points perspectives , central perspective etc…  which are generally classed in two categories : metrics perspectives and conics perspectives .

           

Principle :
The cavalier perspective, also called cavalier projection or high view point, is a axonometric and oblique way to represent a three dimensional object on a flat drawing, that is in two dimensional.

The cavalier perspective is a metric perspective, where the parallel between the planes and the edges are conserved and where the converging lines are reduced. 

The converging lines in perspectives are lines which are perpendicular to frontal planes (planes which are perpendicular to our eyes).

 

How to recognize the cavalier perspective?
If you have a picture which conserve the same proportion but which have an effect of depth, then you have a cavalier perspective. The projection is normally oblique, with three dimensions (x, y, and z) in the space. This depth is present because we have two orthogonal axis, who doesn’t have a coefficient of reduction, and a third one with an angle “a” between 30 and 45° who has a coefficient of reduction “r” between 0.5 and 0.7 and it’s ( a ; r ).

 

Properties :

• Visible segments are drawn in solid lines
• Hidden segments are drawn dashed
• Two parallel lines are drawn by to parallel and two intersecting lines by two intersecting lines
• The middle of a segment is drawn in the middle of the segment drawn before
• Figures located in the frontal plane are drawn in real size
• The angle is between 30 or 45° for all lines starting from the frontal plane (that is all measurements drawn backwards) and they measures the half of the original measurement, that way the cube will look more realistic and in proportion
• The form, edges and orthogonality are respected.

 

But why is it called like that?

This representation was initially used for military fortifications. In French the « cavalier » (literally  the rider, the horseman) was an artificial hill behind the walls that allowed to see the enemy above those walls. So the cavalier perspective was the way the things were seen from this location.

Others explain that this name comes from the way that a rider could see the things on the ground from his horseback.

 

How to represent a cube with this perspective :

• Step 1 : Draw the front view of the cube, which is a square.
• Step 2 : Project the 45 degrees lines from each corner of the square. Don't forget that they measure the half of a side and that the hidden lines are drawn dashed.

  

• Step 3 : Link the lines drawn in step 2.

   

• Some examples :
  This is an example of this kind of representation, the cuboid ABCDEFGH is represented in a central perspective. 

  

 

→ Now this is a cavalier perspective in a coordinate:

 ONE POINT PERSPECTIVE

→ And here is an architectural example : 

 

1 : it’s a main line
2: it’s the central point (the end of mains lines)

______________________________________________________________________________________________________________________

 

 

ONE POINT PERSPECTIVE| NAIMA

Introduction of “One point perspective”

Perspective in the graphic arts is an approximate representation, on a flat surface (such as paper), of an image as it is seen by the eye. The two most characteristic features of perspective are that objects are smaller as their distance from the observer increases; that they are foreshortened, ie that the size of an object's dimensions along the line of sight are relatively shorter than dimensions across the line of sight.

One point perspective is a drawing method that shows how things appear to get smaller as they get further away, converging towards a single ‘vanishing point’ on the horizon line. It is a way of drawing objects upon a flat piece of paper (or other drawing surface) so that they look three-dimensional and realistic.

Drawing in one point perspective is usually appropriate when the subject is viewed ‘front-on’ (such as when looking directly at the face of a cube or the wall of building) or when looking directly down something long, like a road or railway track. It is popular drawing method with architects and illustrators, especially when drawing room interiors.

Important Rules !

There are some important rules to keep in mind when you draw in one point perspective.

• All vertical construction lines are parallel to one another;

• All horizontal construction lines are parallel to one another;

• Given the lack of a second and third vanishing point, this perspective relies on orthogonal construction lines;

• This style of perspective, although convincing, is not always accurate.

 

When to Use One Point Perspective ?

Whenever you need to quickly present a concept of an object or a scene to another person, you're faced with two options: technical blueprints, or a perspective thereof.

Due to the simplicity of this style of perspective, you can quickly convey an idea in a convincing manner, without wasting too much time. Also, although not the most accurate means of perspective rendering, this style is very easily understood by the human brain, and hence also easily understandable by anyone, not just those that studied architecture or technical drawing.

But more often, this style of perspective is used for the following scenarios:

• Architectural interiors of long rooms,

• Object concepts,

• Concept art.

Choosing Your Vanishing Point

Basically, your image is affected similarly to how your object's position, in relation to the horizon line, affects if you see the bottom or top side. If you go very far to your left side, and your object is located on the same side, you risk only being able to view two sides of your object instead of three.

 

Groupe de Carole Clapier, Joaquim Lefort...

THREE POINTS PERSPECTIVE

 

Basically, perspective is a process, a technique used in graphic arts to represent three dimensions objects on a flat surface such as paper. To do so, the drawer has to consider the distance between the object drawn and the obsever. Indeed, one of the main features of perspective is that the object drawn is smaller as the distance from the object and the observer increases, objects are foreshortened.

There are several perspective techniques, like one point perspective, oblique projection perspective generally called cavalier perspective or the one we shall discuss about in what follows, the three points perspective.

Three points perspective is like one or two points perspective, it uses vanishing points where lines converges.  It is mostly used to represent objects seen from above or from below. In three points perspective, segments parallelism is no longer conserved.

 

In order to represent an object, for example a cube, in three points perspective, you must :

1.  Draw the horizon line.
2. On the horizon line, you must place the two first points, one in the right hand side and the other one in the left hand side.
3. The third and last point is placed below or above the horizon line. It depends from which view the object drawn is seen.This points is called the zenith point.
4. As soon as all three points are placed, you can begin to draw. And every segment will be linked to the zenith point and one the point on the horizon line.

 

Generally this perspective technique is rarely used except when artists draw high buildings. Indeed, the three point perspective gives an impression of height even when the zenith point is placed below the horizon line (plunging view). The three point perspective is mostly used in architecture, arts, three dimensions modelling…

 

An example of a reunionese house drawn in three points perspective (the zenith point is placed above, so the obsrver is looking up to the house) :