Seamless looping animation I'm trying to create an animate gif of a boat where there's no discontinuity between the end and the beginning. To do this, I need the sails and flags of the boat to return to approximately their starting location at the end of the animation. Most other questions of this type that I've seen involve something where the kind of motion tends to be cyclic, such as a person walking, or a wheel spinning. But the motion of sails and flags doesn't really fit that description. What can I do to achieve this? My blender file is here
Things like fire etc. I loop in post-production, turns out to be the easiest way and fastest. Just render a bigger chunk of the animation, split it in half and switch the halves. The ends are now seamless but in middle is a discontinuity. Overlap those two parts and blend them with opacity and by pixel-warping if needed (visible edges should be pixel-warped). Picking the right moment for blending is crucial.

Reversing frames and having a ping-pong animation will not work on flags, fire, etc. - That's why it needs to be blended.