Vertical exaggeration is extremely important for
3D models.
Vertical
exaggeration simply means that your vertical scale is larger than
your horizontal scale. A lot of participatory 3D models are done
with a horizontal scale of 1:10,000 (1 cm
= 10,000 cm) and a vertical scale of 1:6,666 (1 cm = 6,666 cm)

To
determine the amount of vertical exaggeration used to
construct a 3D model, simply
divide the real-world units on the horizontal axis by the real-world
units on the vertical axis.

If
the vertical (grid) scale is one 1cm = 5,000 cm and the horizontal
scale is 1cm = 10,000 cm, the vertical exaggeration is 2X
(1:10,000/1:5,000).

Vertical Exaggeration = Horizontal (Map) Scale divided by the
Vertical (Grid) Scale!