OKay this is probably a really basic question but here goes. How do you animate vertices and faces if the structure of them changes during the course of the animation?

Example, animating a knife cutting through paper. If you don;t want the join in the the paper visible before hand i guess you need to split the vertices one at time to show split in the paper gradually progressing along the cut.

The doesn;t seem possible as when i alter the vertices or the faces the animation is lost.


Hope that makes sense, i must be missing something. How does everyone else deal with thi sort of problem?

Thanks in advance for any reponses