Hi Bin,

Since you mention a detector, I assume you are using non-sequential mode. The best way to control multiple objects as a group is to assign them all the same reference object. In your case, you can create a Null object as a dummy object and then reference it in each of the objects you want to move as a group. If you position the dummy object at the center of rotation, then adjusting the tilts of the dummy object will cause the group of objects that reference it to rotate about it.

If the center of rotation is not at the global origin, then a good way to contruct this is to place the dummy object at the center of rotation, select the objects to be grouped, and use the Modify Reference Object tool in the menu to modify the reference of the selected objects to become the dummy object. This will keep them at the same location while modifying the reference.

In the editor, the reference object must precede the objects that refer to it.

Here is what it looks like in a simple example: