title_body: Vertical Flight Paths
upvoted_answer: There is a software called UgCS which I believe should fit your requirements. It allows you to create waypoints with precise location and altitude. There are options like terrain following which allows the UAV to maintain a relatively constant altitude above ground level, a Facade scan tool which allows you to plan a flight path along a vertical plane at a certain distance from a wall, or there is the option to easily create custom waypoints with specific altitudes as shown in this flight path: