PRIN. OF DRAFTING AND SHOP DRAWINGS - OD1641 - LESSON 1/TASK 1
confusion is a double-point projection.
This is clarified by the following axiom:
The end view of a straight line is a point (really a double-point).
Figure 11 is an example of a double-point projection.
The solution is derived
exactly as shown in figure 10 (on the previous page), except for step 3. Points 1
and 2 cannot be joined by an object line because the line extends into the paper
and, therefore, appears as a double point.
This may be visualized if you hold a
pencil horizontal to the ground and rotate it until you are looking directly at the
point, with the eraser end directly behind the point.
If the point represents
point 1 and the eraser represents point 2, you now have a model of the end view of
a line.
FIGURE 11.
END VIEW OF A LINE.
11
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