When an architect creates a model, he/she needs to consider as this is the size of an object relative to another
object, or to a system of measurement.
Value
Proportion
Scale
Perspective
Linear perspective

Three-point perspective

is often used for buildings seen from above (or below). In addition to the two vanishing points from before, one for each wall, there is now one for how the vertical lines of the walls recede. For an object seen from above, this third vanishing point is below the ground.