Geometry instancing and specifying rotation

I'm trying to do something with geometry instancing but I'd like some clarification on what kind of form the rotation attribute is supposed to be in. 

GeometryBatchInstanceAttributes attributes =

        new GeometryBatchInstanceAttributes(Vector3f, Vector3f, Vector3f, ColorRGBA);

The first vector is translation, the second one is scale (x,y,z), and the third one is for rotation…but what "format" if you will is the rotation supposed to be specified in? 

I have a unit vector for what axis I want my instanced geometry to be aligned to but when I put that in here it doesn't do what I expect.

Any suggestions?

This is jME 1?

It's using this rotation vector on a Matrix4f:


     * <code>angleRotation</code> sets this matrix to that of a rotation about
     * three axes (x, y, z). Where each axis has a specified rotation in
     * degrees. These rotations are expressed in a single <code>Vector3f</code>
     * object.
     * @param angles
     *            the angles to rotate.

BTW: In jME 2 it's a Quaternion which makes things easier:
The constructor is

    public GeometryBatchInstanceAttributes(Vector3f translation, Vector3f scale,
            Quaternion rotation, ColorRGBA color)

and I use something like

         Quaternion rotationMatrix = new Quaternion();
         rotationMatrix.fromAngleNormalAxis(angle, Vector3f.UNIT_Y);