3. This is the same box. Who would have
thought from the first picture that there was a
hole going through it. This is why we use
different line types to show “change in
direction”.
4. Visible, Hidden and Center lines
visible – are continuous lines used to depict edges directly visible from
a particular angle.
hidden – are short-dashed lines that may be used to represent edges that
are not directly visible.
center – are alternately long- and short-dashed lines that may be used to
represent the axes of circular features.
Visible line
Hidden line
Center line
Top View Isometric View
5. This is a top view of an object.
4
Top View
4
Is this object a 4x4 box? Lets look at the front
view to give us another prospective.
6. As you see this object is more complex that it first appeared. The
visible line should have been your first clue.
Visible line
Top View Front View
What have we learned so far?
1) Objects are not always what they seem.
2) That objects can not be clearly understood
without different line types and with just one view.
7. 6 Principle Views
There are six principal views in a multi-view orthographic
projection. These are the front, back, top, bottom, and left-
and right-side views.
8. Principal Dimensions
The three principal dimensions of an object are width,
height, and depth.
Now that we are familiar with the different views and the
principal dimensions, lets look at some examples.
