In perspective projection, if a line segment joining a point which lies in…
2016
In perspective projection, if a line segment joining a point which lies in front of the viewer to a point in back of the viewer is projected to a broken line of infinite extent. This is known as _______.
Answer: C. Topological distortion — Answer: Topological distortion Explanation: In perspective projection, points are mapped to the image plane by rays from the viewer (center of projection). If…
- A.
View confusion
- B.
Vanishing point
- C.
Topological distortion
- D.
Perspective foreshortening
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Correct answer: C
Answer: Topological distortion
Explanation: In perspective projection, points are mapped to the image plane by rays from the viewer (center of projection). If a line segment has one endpoint in front of the viewer and the other behind the viewer, the segment crosses the projection plane. Points near that crossing map arbitrarily far from the image center, so the projected image becomes discontinuous and extends toward infinity. This discontinuous, broken-line projection is called topological distortion.
A point approaching the projection plane projects to positions with arbitrarily large coordinates on the image plane (moves toward infinity).
When a segment crosses the projection plane, the projection is split into parts that do not join smoothly; the image appears as a broken line that can extend to infinity.
Related terms: vanishing point refers to where parallel lines appear to meet; perspective foreshortening refers to apparent shortening with depth. Neither term describes the broken infinite projection caused by crossing the viewer plane.