PERSPECTIVE VARIABLES
Angle of View
Digital Viewpoints
The orientation of the central axis of vision
(CAV) and the picture plane(PP) relative to
an object determines which faces of t he
object are visible and the degree to which
they are foreshortened in perspective.
Inconstructinga perspective by hand, we must have experience in setting up the
st ation point and t heangleof view to predict and achieve a reasonable outcome. A
distinct advantage in using 3D CAD and modeling programs is that once the necessary
data is entered for a three-dimensional construction, the software allows us to
manipulate the perspective variables and fairly quickly produce a number of perspective
views for evaluation. Judgment of what aperspective image conveys, whether produced
by hand or w the aid of the computer, remains the responsibility of itsauthor.
ith
• The more a plane is rotated
away from PP, the more it is
foreshortened in perspective.
• The more frontal the plane is, the less it is foreshortened.
• When a plane becomes parallel to PP, its true shape is revealed.
PERSPECTIVE DRAWINGS
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