I've never used flow fields, so I don't know whether it would be tricky to implement them in a 3d space. The implementation shown in the video basically operates on a 2d plane, which probably is underachieving the environment of a 3d space game.

If I'm not mistaken, the flow direction around obstacles depends on the position and the movement direction (or destination) of the avoiding agent or group. So in my understanding, when you have multiple agents moving into random directions, each agent would possibly require its own flow field. This seems to be logical. By moving a group of agents, each agent could use the same flow field, what prabably makes this technique very efficient for controlling large numbers of units (in groups) in RTS games.

Well, I'm just guessing here and I really don't want to lead you astray. : )
But at a first glance those flow fields don't seem to be the best solution for your space game (unless there are large groups of space ships involved, of course).


Other collision and obstacle avoidance techniques might be an option for your game, too. In space you can benefit from the freedom of movement and (most propably) the absence of dead ends.

Have you already tried some other techniques whether they work for you?