## Lesson 09 – Perspective of points in given positions on a line perpendicular to the picture plane

To set points on a line perpendicular to the picture plane we can use co-planar straight lines that form an angle of 45° with the picture plane.

## Lesson 7 – Perspective of any plane perpendicular to the picture plane

This lesson is dedicated to the perspective of any plane that is perpendicular to the picture plane. It means that we will consider vertical planes, and inclined planes, too.

## Lesson 6 – Perspective of points that belong to the straight line r

This lesson is dedicated to the perspective of the points that belong to line r and, particularly, to some of the points that are notable because of their position.
The perspective of a point P, that belongs to line r, is the intersection of the projecting line (OP) with the perspective r’ of the line r.

## Lesson 5 – Perspective of a line perpendicular to the picture plane

Any straight line perpendicular to the picture plane has the vanishing point coincident with the principal point .

## Lesson 4 – The reference plane

This lesson is dedicated to the perspective of a plane, particularly the reference horizontal plane π1.

## Lesson 3 – The Distance Circle

How to fix the position of the projection centre in space.

## Lesson 1 – The World as it looks, and as it is

There are two ways to experience the World that surrounds us: as it looks, and as it is.
The Perspective emulates the human vision of the World, like it looks.