use a cobble floor. make sure you have floor information for what you want to track (this is crucial, you see some VFX making of use half tennis balls, you can use anything as long as it contrasts with the floor when you move your camera).
To occlude the actor (if he/she doesn't cast shadows), track your 3d object, generate the scene, use your actor as foreground and background, in the middle (of the compositing layers in the compositor) you'll use your 3d object. So when the actor pass in front of the object, it shows in front (actor is top layer, 3d object is behind).
When your actor is behind the object, make sure your 3d object is composed at the top and the actor as the background.
Then tere is the "middle zone" where you'll need to occlude certain parts first (hands, legs, head, etc..) you'll need to rotoscope them using the mask node.
Here's a short video on how to use them:
You need to plan your shot and movement. If you need your actor to do interactions with the object, you'll need to green screen him/her and bring the footage sequence as image plane. Then proceed to do compositing directly on the 3d track generated scene from your footage. You need to know your sensor's size to match lens distortion.