Well, you can create an hour long composition. Use your favorite particle program of choice and make snow.
Or you can create a 6 minute composition of snow, add that composition to a five minute comp. Split it in the middle (ctrl+shift+d on a pc) then move the first half to the end and the second half to the beginning and then keyframe the opacity of the top layer so that it crossfades. You can try a whole minute or just a couple of seconds and see which one you like. That should give you a pretty seamless loop. Note; the numbers I chose are arbitrary, so long as the snow comp is longer than the final comp you should be good.
I hope that made sense.
Do you need help with the actual creation of the snow?
- The Great Szalam
(The 'Great' stands for 'Not So Great, in fact, Extremely Humble')
No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.