I'm super new to this sort of thing, but this video game (I know it's weird) in the first few seconds, has the ground appearing out of nowhere for this person. Can a similar effect be done simply through CGI nowadays and look realistic? Or would that be something really requiring a lot of time and money? Or the reverse, running and ground chunks disappearing underneath the person.
http://www.youtube.com/watch?v=7X8C6CMiuR8
http://www.youtube.com/watch?v=7X8C6CMiuR8