Rotation of objects is quite frequently required. Even if your are not including an object definined in another file, you most likely will need to rotate a primite shape to incorporate it into your world.
Rotation is specified as an option of the Transform node. Generally, the syntax for a rotation is:
Transform {
rotation 0 1 0 1.57
child ...
}
Note that the first three arguments to the rotation field are the axes to rotate the object about.
In this case, we only rotate about the Y axis. The last argument is a floating point value
representing the number of radians to rotate the object. Note that the conversion from
degrees to radians is # of degrees*PI/180.