Discuss a sight ray. What is it and what is its purpose? What ...

[bcretired]

Discuss a sight ray. What is it and what is its purpose?
 
  What will be an ideal response?

Question 2

If you want to feature the ceiling in a perspective, what would you do differently than a perspective showing the normal view of a room?
 
  What will be an ideal response?

[nathang24]

Answer to Question 1

It is a construction line, used to project lines from the station point, parallel to the walls until
the line reaches the picture plan.. Since it is a construction line, it will be erased later, but it is
a line that helps you to construct the perspective grid accurately. Where the line intersects
the picture plane, project down to the horizon line and mark it LVP or RVP. All horizontal lines
will converge to one of these two points.

Answer to Question 2

You would decide your eye level height at a lower height than the common 5'-0 standing height.
For a sitting height, 3'-6 is a common choice. This will give you a view of the features of the ceiling
rather than the tops of items, as common in a standing height.