I have a clip with a person standing still and the camera turns around her 360. I want to add an object on her which is not rotating like she does but follows the camera movement so it looks like it is on her. Tried the trackers and mocha but couldn't manage. Any suggestions?
What is the camera angle? If you can see the plane of the ground you could get a track and convert it to a 3d null instead.
What is the detail around the subject? Is it static, such as walls, trees etc or is it moving?
You'll probably first need to mask out the actor as a foreground layer, then behind her on a new layer, try to track the ground in perspective with a largish layer. Depending on the speed of the rotation you may need to up the angle value in the tracking parameters.