With the development of unmanned aerial vehicle (UAV) technology and the prices of drones go down, they become more popular in a wide variety of tasks. In particular, drones are increasingly widely used by professional, as well as amateur photographers and cinematographers for capturing aerial imagery and videos.
However, generating high quality aerial video footage with drones is highly challenging, even for experienced cinematographers. In addition to controlling the trajectory of the drone, one must simultaneously control the camera's direction. The common task actually requires two people to capture a drone video, one to pilot the drone, and another to control the camera at the same time. Furthermore, limited battery life and quickly changing lighting conditions make it difficult to rehearse the flight, or repeat the capture, if mistakes were made during the first attempt.
Recently, researchers have addressed problems such as designing smooth drone trajectories that interpolate user-specified keyframes (P. 2015. An interactive tool for designing quadrotor camera shots. ACM Trans. Graphics 34, 6, 238), and ensuring that planned trajectories are dynamically feasible (P. 2016. Generating dynamically feasible trajectories for quadrotor cameras. ACM Transactions on Graphics (Proc. SIGGRAPH 2016) 35, 4). In the work “An interactive tool for designing quadrotor camera shots”, the process consists of prototyping a trajectory in a 3D simulator before executing it automatically in the real environment. The virtual trajectory is designed by creating an ordered collection of manually positioned viewpoints (keyframes). In “An interactive tool for designing quadrotor camera shots”, the order of the keyframes is also specified by the user. A specific C4 continuous trajectory is created between the keyframes (C4 continuity ensures that the path obeys the physical equations of the quadrotor's motion). The feasibility of this trajectory is then analyzed and reported to the user, so she/he can iteratively alter the keyframe order. More recent work addresses the feasibility sue in an automated way “Generating dynamically feasible trajectories for quadrotor cameras” using an optimized time-warping of the trajectory.
Similarly to “An interactive tool for designing quadrotor camera shots”, Gebhardt et al. propose a design tool where a camera path can be drawn and edited in a virtual environment and then optimized to ensure its feasibility. Given the multiple constraints (such as avoiding collisions), the optimization process does not guarantee to respect the user inputs: a trade-off is necessary between user inputs and conflicting constraints.