Perspective Practices, Continued
Measuring-line
The measuring-line method of constructing perspective drawings is used less
method of
than the plan view method. Use the measuring-line method of constructing
perspective
projection
perspective drawings when you do not have scaled orthographic drawings of
the object. The measuring-line method works best when used in simple
constructions of linear objects because of the amount of mathematical
computations required to determine line lengths.
To construct perspective drawings using the line-measurement method, use
this table:
Step
Action
1
Draw a horizon line and ground line.
2
Arbitrarily place two well-separated vanishing points, one on either
side of the object (VPL and VPR).
3
Select surface (A) and place it parallel (one-point perspective) or
at an angle (two-point perspective) to the picture plane.
4
Extend visual rays from the station point to the vanishing points.
5
Measure height along the dimension that is parallel to the picture
plane. This measurement will appear in true length.
6
Measure the dimensions of width and length against the GL. Draw
perpendicular lines to intersect the receding lines leading to the
vanishing points.
7
Darken all object outlines.
Continued on next page
