1. Engineering Design and Presentation
Introduction to Pictorials, Specifically Isometrics
UNT in partnership with TEA. Copyright ©. All rights reserved.

2. Pictorials break down into two (2) groups
Group #1= Perspective or Central Projection.
Group #2= Parallel Projection that includes Orthographic (Multiview), Oblique, & Axonometric.
UNT in partnership with TEA. Copyright ©. All rights reserved. 2

3. Group #1: Perspective Drawings
Perspective drawings produce the view that is most realistic.
A perspective drawing is often referred to being the “camera” or photo view.
There are three main types of perspective drawings depending on how many vanishing points are used.
These are called one-point, two-point, and three-point perspectives.
UNT in partnership with TEA. Copyright ©. All rights reserved. 3

4. Group #2: Oblique and Isometric Drawings
Obliques Isometrics
UNT in partnership with TEA. Copyright ©. All rights reserved. 4

5. UNT in partnership with TEA. Copyright ©. All rights reserved.
Oblique Pictorials
Oblique pictorials don’t look as realistic as perspectives or isometrics because the side or depth view looks distorted or “stretched out”. However, circular shapes in the front view aren’t distorted and that makes them easier to draw.
If you do have to draw an oblique, cabinet projection is the method you use because the depth is halved making it look more realistic. 5
UNT in partnership with TEA. Copyright ©. All rights reserved.

6. Axonometric Projections
We are going to focus only on Isometric’s, but there are others.
There are three (3) types:
Isometric: all angles are equal or 300.
Dimetric: only the top & right side view are the same angles.
Trimetric: none of the angles are equal.
UNT in partnership with TEA. Copyright ©. All rights reserved. 6

7. UNT in partnership with TEA. Copyright ©. All rights reserved.
Why draw Isometrics?
They are BOTH true size, or dimensionally correct, and visually pleasing to the eye.
Think of them as a combination of a perspective and an oblique drawing, using the best from each.
UNT in partnership with TEA. Copyright ©. All rights reserved. 7

8. Oblique vs. Isometric. Which one is the most realistic looking?
UNT in partnership with TEA, Copyright ©. All rights reserved. 8

9. Draw back of Isometric? Circles in an Isometric
Circles distort shape, or become ellipses, when drawn in an isometric sketch.
To sketch an isometric circle, locate the center and then sketch the box that would enclose the circular shape. Draw the ellipse tangent to the lines of the box. This is very similar to how you’d sketch a circle, just an angle.
UNT in partnership with TEA. Copyright ©. All rights reserved. 9

10. UNT in partnership with TEA. Copyright ©. All rights reserved.
Hidden Lines
Generally, you will NOT draw hidden lines in any pictorial.
You draw the object so that they aren’t necessary to be drawn to show the shape of the object.
You assume that holes go all the way through unless it’s noted otherwise.
UNT in partnership with TEA. Copyright ©. All rights reserved. 10