# Types of Projection in Computer Graphics

__Projection in Computer Graphics:__

Projection is a technique which is used to transform a 3D object into a 2D plane. It is defined as the mapping or transformation of the object in a view plane. The view plane is displayed surface.

__Types of Projection:__

In Computer Graphics, there are mainly two types of projection, these are:

1. Parallel Projection

2. Perspective Projection

### Parallel Projection:

When the centre of projection situates at an infinite distance such that the projectors are parallel to each other. These type of projection says **Parallel Projection**.

In **Parallel Projection**, the image points are found at the intersection of the view plane with parallel projectors drawn from the object points in a fixed direction. The two basic types of parallel projection are:

i. Orthographic Projection

ii. Oblique Projection

#### Orthographic Projection:

It occurs when the direction of projection is perpendicular in which the direction of projection isn’t parallel to any of the three principal axes.

#### Oblique Projection:

When the angle between the projectors and the plane of projection isn’t equal to 90 then the projection says **oblique projection**.

There are two types of oblique projection, these are:

i. Cavalier Projection

ii. Cabinet Projection

#### Cavalier Projection:

The direction of projection choose that there is no foreshortening of lines perpendicular to the plane of projection.

#### Cabinet Projection:

The direction of projection choose that the lines are perpendicular to the plane of projection is foreshortened by half their lengths.

### Perspective Projection:

A **Perspective Projection** of a 3D object, we transform points along projection lines which are not parallel to each other and coverage to meet at a finite point. It says **Projection Reference Point** or **Center of Projection**.