Going Beyond with 3D Transforms - CSS3 Foundations - page 213

Figure 13-3 The empty div, moved back 500px in the 3D space of the main container.
Now look at how perspective-origin can affect this 3D effect by applying the following declaration to the
#main rule set:
-webkit-perspective-origin: 30% 30%;
As Figure 13-4 shows, when you change the perspective-origin , the element is no longer viewed straight on.
The viewer now sees the element as if looking at it from an angle.