neither will work I suppose. applying inverse rotation of object to camera does not make sense in this case. ie: when camera is at origin, rotation of object does not change object's location at screen, but when that rotation is applied to camera, camera's field of view changes.
I guess the right way is:
* calculate reverse object translation
* rotate that by inverse of object rotation
* move camera to that point
* rotate camera by object rotation
BTW, can I use a detached camera in Interact2D.reproject2D3D? i.e. a camera which is not actually used to render scene