1. Engi 1504 – Graphics Lecture 4: More on visualization
Review of isometrics
Adjacent and similar areas
Projection studies and assignment 4

2. Isometric Example

3. Isometric Sketching: Steps
Visualize object by breaking into known shapes (circles, prisms, etc)
Define overall size defining width, height and depth
Sketch known shapes
Connect ‘loose ends’
Darken

4. Adjacent Areas
Adjacent areas are surfaces that reside next to each other
The boundary between surfaces is represented by a line indicating a change in plane

5. Many possible solutions
Adjacent areas represent surfaces that are:
At different levels
Inclined or oblique
Cylindrical
A combination of the above
Use all views necessary to represent the object clearly

6. Similar Areas A surface always appears as either a line or as an area
When a surface appears as an area it may be true size or distorted.
Only angles and lengths of sides are changed, the number of sides and their sequence are unaffected

7. Similar Areas cont. Rule of configuration:
Every plane surface, regardless of shape, always appears either as an edge or as a figure of similar configuration

8. Similar Areas cont.
If a surface shows similar configuration in two views and appears as an edge in the third view:
Inclined surface
An inclined surface is perpendicular to one of the principal planes of projection and inclined to the others.
If a surface shows similar configuration in all views:
Oblique surface

9. Inclined and Oblique Surfaces
(vertical)
Inclined
Inclined
Oblique

10. Inclined and Oblique Surfaces
Based on what we’ve learned, where is the error?
Remove corners
The corners should be removed since the top surface must have the same shape as the front view (and the actual object).

11. Projection Studies

12. Projection Studies

13. Finding Missing Information
Today’s assignment is to complete the views of an object that are missing some information.
Let’s looks at Example 2.8 in the text.

14. Finding Missing Information
Given that the front view is incomplete and the side view is complete, draw the top view, complete the front view, and sketch the isometric

15. Finding Missing Information
Front view: there is no line corresponding to the bottom of the slot

16. Finding Missing Information
Top view: project the width, depth and slot points

17. Finding Missing Information
Darken lines and complete the sketch

18. Class Assignment 4
Sketch the missing view (or missing lines) and an isometric for Questions 104 and 106 in workbook.
Notes:
the missing views must be completed using your drawing instruments
the isometric must be done freehand