Custom collision maya and unreal very important

I’ve been building my map for a video game and I’m trying to learn how to make custom collision. Usually unreal makes a box and area I don’t want, How will I go about doing this for door and etc?

If I’m understanding your question this should answer it for you:

https://docs.unrealengine.com/latest/INT/Engine/Content/FBX/StaticMeshes/index.html#collision

I’ve used this and it only makes about 4 collisions when i try to make 10 or twenty