Isometric Projection

ISOMETRIC PROJECTION

Isometric projection is a pictorial projection of an object in which the three dimensional view of the object is shown. The pictorial view is obtained by keeping the object in such a way that all the three mutually perpendicular geometrical axes are equally inclined to the plane of projection.

The three principal reference axes for the isometric view are shown in Fig. 17.1(a), which are equally subtended between any two reference axes as 120°. While constructing the object in three dimensions, the principal axes x, y and z are taken as shown in Fig. 17.1.(b), taking z axis vertically upward so that the axes x and y are making angles of 30° with horizontal.

Three measurements length, breadth and depth are measured along x, y and z axes respectively. An object (Rectangular prism) drawn with reference to the principal isometric co-ordinate axes is shown in Fig. 17.1 (c), known as the `Isometric View'.

In Isometric projection also, the projectors follow the rules of multi-view projections. ie., they are parallel to each other and perpendicular to the plane of projection. But in Isometric projection, all the three axes and the lines parallel to them, respectively, have the same ratios of foreshortening when projected to the plane of projection.

The other principles of Isometric projection are explained below.