Parallel vs Perspective Projection
Parallel projection
√ Distance from the observer to the object is infinite projection lines are parallel – object is positioned at infinity.
√ Less realistic but easier to draw.
Perspective projection
- Distance from the observer to the object is finite and the object is viewed from a single point – projectors are not parallel.
- Perspective projections mimic what the human eyes see, however, they are difficult to draw.
Orthographic projection is a parallel projection technique in which the plane of projection is perpendicular to the parallel line of sight. Orthographic projection technique can produce either pictorial drawings that show all three dimensions of an object in one view or multi-views that show only two dimensions of an object in a single view. These views are shown in figure 5.
Figure 5. Orthographic projections of a solid showing isometric, oblique and multi-view drawings.