Why the success of mega-blockbusters is relevant at the artsy, auteur-driven Cannes Film Festival

When the 68th edition of the Cannes Film Festival opens Wednesday, once again two movie cultures will collide on the city's sunny, crowded Croisette.Hotels along the seaside throughway will be festooned with posters for upcoming blockbusters, a few of which are actually playing in the festival this year: "Mad Max: Fury Road," the fourth installment of the post-apocalyptic epic, will have its premiere here this week, as will Disney's "Inside Out." Meanwhile, the core competency of the festival --...