you would think there are enough animation tutorials out there but for my own sanity I'll add another one ;) just to make sure we'll have some variety in the falling snow action...
it's easy, I promise.
prepare the base you wanna add your "artificial snow" to...
step 02: big flakes
make a new layer and paint some snowflakes in white on this layer.
you can make your life much easier if you change your brush settings to randomly place the flakes:
choose the Soft Round 5 px brush
in your Brushes Palette change the Spacing to around 500 % (under Brush Tip Shape)
under Shape Dynamics set the Size Jitter to 100 %
and finally set the Scatter to 1000 % (under Scattering)
you're ready to paint your first snow layer. Make sure no big flake touches the edge of your icon (it won't look smooth later if they get cut on the edges), but paint as close to them as possible.
if your flakes get cut just erase them.
step 03: small flakes
make a new layer and change the Diameter to 3 px (under Brush Tip Shape)
leave everything else at the settings we've just used to create the first snow layer.
now paint some tiny flakes.
step 04: Preparing your Canvas
Change your Canvas size to three times of its original height (i. e. when you're working on a 100x100 icon, change it to 300 px)
make sure it's not the Image size you're changing (there would be ugly stretching) but the Canvas Size
Set the Anchor to the lower middle.
you should have something like this now...
step 05: Preparing your snow
Select your first snow layer with the big flakes and duplicate it.
move the new layer 100 px in the upwards direction.
you can do this rather easily by selecting the move tool, and then pressing the up arrow while holding the shift key ten times (shift while moving means 10 px steps, so 10 multiplied with 10... you'll get it... *g*)
merge these two layers together (select the upper one and press ctrl+e)
select your small snowflakes layer and duplicate it twice.
move the first copy 100 px upwards, and the second one 200 px. (i.e. while holding the shift key click the up arrow ten/twenty times)
merge these three layers together.
you should have something like that now (I colored the background, just so you can see it better...
step 06: Back to your Canvas size
We're changing the Canvas size back to normal.
make sure your Anchor is again in the lower middle...
and we're back to normal...
step 07: get ImageReady
Switch to ImageReady.
Duplicate your current first frame.
With your second frame still selected go to your Layer Palette and select the Big Flakes Layer.
Move it 100 px down (press ten times the down arrow while holding shift)
then select your Small Flakes Layer and move it down 200 px (20 times while holding shift)
step 08: Tweening
In your Animation timeline press the tweening button. (you still have the second frame selected at this point)
Make sure you have All Layers selected, as well as Position tagged.
Choose the number of inserted pics.
The more pics, the smoother the animation. But: the more pics the bigger the file size...
Try to find a compromise, this may need a little experimentation...
Something around 15 should look OK...
Delete the last frame in your animation timeline.
The first and the last frame are exactly the same at the moment, so if you don't delete it, it will look like the animation stops for a tiny moment here.
You can make it look a little slower, by adjusting the delay time.
Select all pics in the strip, and then change the delay time to 0.1 sec
step 09: Optimization
Get it under the 40k limit of LJ.
You know, do the usual things, make it a tiny bit lossy, reduce the colors...
or for example cheat and set a big white border around it to make the file size smaller...
step 10: variations
use bigger flakes (brush size of 12 for the big ones and 6 for the small ones)...
actually the optimization is easier with bigger flakes... or make it slower/faster...
that's not that hard, is it?
for my sanity, please make some new snow animations? pretty please? *puppy eyes*
and Have Fun! :)