Another environment hazard, like the Nebula. This one's a little more dangerous if you couldn't tell.
We basically needed an animated storm cloud to be placed around certain levels. At first I considered a more rounded direction for the appearance, but ultimately I wanted it to look much different than the Nebula since they're 2 separate hazards. Opted for something a little more angular and hostile looking.
Truth be told I had no real idea of how to animate a cloud, so I looked up some reference first in the form of time lapses depicting storm formations.
After watching these a few times, I realized that it would take a lot of frames to get a realistic billowing effect for clouds. Even at such high speeds, you can see that in these videos the clouds still move pretty slowly. I didn't want to waste too many frames on this single animation since the game no doubt will have many more to include down the road.
Ultimately I figured it was best to forego realism and focus on communicating the overall 'idea' of a cloud. Even if the movements weren't as smooth as an actual cloud mass, I could get the basic movements of the clouds, the flashes of lightning, and the proper tones of grays to get the idea across to the player.
Everything was drawn first in Illustrator, then broken up into separate files according to how they would move and imported to Flash. I knew the bottom layer would comprise the main mass and move subtly as a unit.
Also had a separate file for little cloud bits here and there, which was something I took note of from the time lapses.
Yep. Just a plain old square...
These were imported into Flash where tweening makes small movements like the subtle up and down motion a breeze.
I wanted some to be affected by the bolts of lighting. In order to do this, I made a copy of the appropriate clouds with slightly different shading in Illustrator, like so:
And layered the lit up cloud over the normal one in Flash. When the animation was on a frame where lightning was nearby, the lit cloud layer was turned on; otherwise it was made invisible. Kind of like an on/off switch.
Put it all together and you have a lightning cloud! I hope you've enjoyed this wall of text, and maybe it's even given you some ideas you can use in the future. :D