The previous posters are correct that AE is not necessarily the best tool out there for this, but as was previously mentioned, it could do it.
If you want the camera to be moving, it will make things much more difficult. You can do this in AE with a camera on a tripod relatively easily. You take a shot without the skateboarder in it, have him do his thing, then using rotoscoping, cut out the skateboard. However, depending on the trick he does, you may have to paint in the bottoms of his shoes, his shadow, parts of his legs/trousers, etc..
If you want to do a shot with the camera moving, it will take quite a lot of work and swearing or a motion control rig, work and swearing.
It also takes a lot of planning
– The Great Szalam
(The ‘Great’ stands for ‘Not So Great, in fact, Extremely Humble’)
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