what are the variables Default Horizontal and Vertical Terrain Wibble?

[Kitebuilder]

Hello
At scrolling through the level-variables i found these:
"Default Horizontal Terrain Wibble"
"Default Vertical Terrain Wibble"

What do they mean?
How much the terrain tiles are bend and stretched out of the perfect cube-shape?

[Quuz]

it is better not to touch these parameters) there are many other interesting strings of variables)