public Vector4f normalize() {
//        float length = length();
//        if (length != 0) {
//            return divide(length);
//        }
//
//        return divide(1);
        float length = x * x + y * y + z * z + w * w;
        if (length != 1f && length != 0f) {
            length = 1.0f / FastMath.sqrt(length);
            return new Vector4f(x * length, y * length, z * length, w * length);
        }
        return clone();
    }
<code>normalize</code> returns the unit vector of this vector.

@return unit vector of this vector.
jme3-core/src/main/java/com/jme3/math/Vector4f.java