I saw a lot of picking code opengl-es, but nothing worked. Can someone give me what am I missing?

My code is (from tutorials/forums)

Vec3 far  = Camera.getPosition();
Vec3 near = Shared.opengl().getPickingRay(ev.getX(), ev.getY(), 0);

Vec3 direction = far.sub(near);
direction.normalize();

Log.e("direction", direction.x+" "+direction.y+" "+direction.z);

Ray mouseRay = new Ray(near, direction);

for (int n=0; n<ObjectFactory.objects.size(); n++) {
    if (ObjectFactory.objects.get(n)!=null) {
        IObject obj = ObjectFactory.objects.get(n);

         float discriminant, b;
         float radius=0.1f;

         b = -mouseRay.getOrigin().dot(mouseRay.getDirection());
         discriminant = b * b - mouseRay.getOrigin().dot(mouseRay.getOrigin()) + radius*radius;

         discriminant = FloatMath.sqrt(discriminant);

         double x1 = b - discriminant;
         double x2 = b + discriminant;

         Log.e("asd", obj.getName() + " "+discriminant+"   "+x1+" "+x2);
    }
}

my camera vectors:

//cam
Vec3 position   =new Vec3(-obj.getPosX()+x, obj.getPosZ()-0.3f, obj.getPosY()+z);
Vec3 direction  =new Vec3(-obj.getPosX(),   obj.getPosZ(), obj.getPosY());
Vec3 up         =new Vec3(0.0f, -1.0f, 0.0f);
Camera.set(position, direction, up);

and my picking code:

public Vec3 getPickingRay(float mouseX, float mouseY, float mouseZ) {

    int[] viewport      = getViewport();
    float[] modelview   = getModelView();
    float[] projection  = getProjection();

    float winX, winY;
    float[] position    = new float[4];

    winX = (float)mouseX;
    winY = (float)Shared.screen.width - (float)mouseY;

    GLU.gluUnProject(winX, winY, mouseZ, modelview, 0, projection, 0, viewport, 0, position, 0);

    return new Vec3(position[0], position[1], position[2]);
}

My camera moving all the time in 3d space. and my actors/modells moving too. my camera is following one actor/modell and the user can move the camera on a circle on this model.

How can I change the above code to working?