Lecture 17 : Projections of points

Lecture 18 : Projections of points in 2nd, 3rd and 4th quadrant

Figure 4. The multiview drawing of the point P lying in the second quadrant.

Point in the Third quadrant

Projection of a point P in the third quadrant  where P is 40 mm behind VP, 50 mm below HP and 30 mm behind the right PP is shown in figure 5.


Since the three planes of projections lie in between the observer and the point P, they are assumed as transparent planes. After the  point P is projected on to the three planes, the HP and VP are rotated  along the direction shown in figure 6, such that the HP and PP is in plane with the VP. The orthographic projection of the point P lying in the third quadrant is shown in figure 7.

Figure 5. Projection of a point P placed in the third quadrant

In the third angle projection, the  Top view is always above the front view and the  Right side view will be towards the right of the Front view.

Figure 6. shows the sense of direction of rotation of PP and HP.