For the new 3D version of “Titanic” that?s now in theaters, director James Cameron marshaled an army of visual effects technicians who spent over a year converting the 1997 film, frame by frame, into 3D.And those technicians would probably buy the owners of a Madison-based software company a round of beers, to thank them for making that time-consuming job a little easier. If the rotoscopers are doing their jobs right, audiences won’t even notice their work, said Perry Kivolowitz, one of the four partners in SilhouetteFX and a computer science professor at UW-Madison.