How activate some action like ( open door, play some animations ) when my cam pass trought collider, when i play with my render senquencer

Hey everybody, i have two problems,

  • 1st, i don’t know how to set up a main camera. When i press play, the view that i see, isn’t what i want, the engine create a new one from nowhere…

  • 2nd, I would like to know how activate some action like ( open door, play some animations ) when my camera pass trought collider that i set up for which one action when i play with my render senquencer for a image sequence .