Now that you've got used to some 3D techniques, it's time to introduce some more technical features of the Android graphics APIs. In this example, we will use matrix math to rotate our jigsaw in the three-dimensional space. But don't worry! The API abstracts the actual mathematics into nice easy concepts.
Using these techniques, we essentially think of the thing we are rotating as a set of coordinates to which we apply a mathematical formula. That formula uses what we call a matrix to create the impression that the view is being moved in three dimensions.
This next example makes use of
Rotate3dAnimation from the Android example sources. It is provided under the Apache license, and is a useful illustration of how to do 3D transformations ...