If the pilot defines a Mission as using the Curved Turns path, support the performing of actions at Waypoints actually arrived at (by using a manually set “0 ft” curve at desired Waypoints).
Thus actions could be performed at some Waypoints as desired by pilot.
I’m frustrated by this omission, too. I usually want to start video recording only after stabilizing at Waypoint 1, while focused on a particular starting POI. Works fine if curves are disabled, but not if curves are enabled, even with curve radius set to zero for the given waypoint. Why?
Having the option of executing actions at any waypoint where the curve size is zero would certainly provide more flexibility. As a software developer, I am guessing that this feature is a difficult one to implement. Currently, setting the “Path Mode” to “Straight Lines” is a global switch for waypoint actions where each line segment may be treated as an individual path with a start and an end. This allows one to execute various options at the start or end of that segment.
However, with curved paths, even if the curve size is set to zero at a waypoint, may not allow the portions between waypoints to be handled as individual segments. If so, to support such a feature would require that as the drone travels along the path, its current position would have to be continuously compared to all waypoints to see if it is close (you wouldn’t be able to test for equality) to a waypoint and then execute any actions defined for that waypoint.
I could be all wrong about this, but this is my best guess as to why actions are supported the way they are.
I think you’re right about it not being trivial to implement, and the clue you identified of setting a global flag tor straight or curves is insightful. However, I also think the Litchi software overall is incredibly sophisticated, and that’s due to some very talented software developers. To create the curve the drone is following, the software must already know the three waypoints involved, know which of those is in the center and certainly knows the drones position. I would think monitoring r^2 (square of the distance from drone to mid-waypoint) would be straightforward: when it starts to increase do the actions. Easy for me to say with my near-perfect ignorance of the details, of course. Curves get rid of the slight pause at waypoints I see in my videos, most apparent when flying straight line missions.
Yesterday I used a competing app (iOS only) and it has similar “curved turns” functionality. Yet it allowed me to perform actions on the first and last waypoints.
All other waypoints were curved turns so “action” functionality was not tested on that flight.
The manual suggests that actions can be performed at intermediary waypoints actually reached (no curve) - will test that out on my next experimenting flight.