Realistic CG Tornado in Adobe After Effects
note: Originally This tutorial was featured at CGTalk, 3D Attack magazine and Video Copilot. So, I thought I should post it here.
Now there’s probably a hundred ways to do this, this is just one way, So here goes the tutorial, enjoy!
I wanted to share a tutorial I did for making a realistic tornado in After Effects (I am using AE CS3). The only thing you’ll need is good storm footage and the effect called CC Mr. Mercury.
I actually got the idea to do it after I finished Andrew Kramer’s “Water Drop” tutorial.
I started playing around with the filter effect called CC Mr. Mercury. And I found that I could indeed create a very realistic, pretty passable, spinning debris field. I’m sure there are a ton of ways to create good tornadoes, but I thought I would share mine.
The key is good storm cloud footage. Without it, you’ll be hard pressed to get it looking real. Or end up trying to do it in 3D which is even more difficult. Not impossible, but not easy either, I know I’ve tried (I use Cinema 4D 10).
So here goes. I bought Video Copilot’s “Real Clouds” for $75 you get a lot of great cloud footage. Real Clouds here: http://www.videocopilot.net/products/realclouds/
I used 03.mov, the one that definitely looks like a tornado would spawn out of.
To get a general idea of the animation you can see it over at youtube. I just uploaded the HD version of this tornado.
1) Drop in the storm cloud footage, 1st layer.
2) Duplicate that 1st stormy layer to make a second storm layer and flip it vertically.
3) Now find a good place in that footage for a funnel. It takes some creativity here. I just picked a spot of clouds that would be suitable for a funnel.
4) Put a mask around your desired spot of the vertical clouds for the funnel. Now remember this is all the way I did it with the storm clouds I used. Your stormy clouds may be different, so be creative and look at real tornado footage and photos for ideas. Shape your funnel to your desire. Your sort of limited in certain footage so be sure to shape the mask so that the funnel looks like it’s “twisting”. It’s all about illusion.
Oh and don’t forget to feather!!! or else you’ll have sharp edges on your funnel, a big No-No.
5) Rename this layer “funnel” for clarity. I put a second mask on this same layer (Mask Subtract) so I could feather out the top of the funnel so it would blend well into the bottom of the dark clouds.
6) I animated the mask (mask 1, leave mask 2 alone) so that my funnel would start to come down out of the clouds to the bottom of the scene.
7) That’s it for the funnel other than I keyframed the position for it to move left to right in the scene following it’s debris field which I’ll explain next.
8) The debris field was fun, and adds some more realism to the tornado. Now some of you may decide of other ways to do this, I just did it using CC Mr. Mercury after I toyed around with the effect.
9) Just like in Andrew Kramer’s “Water Drop” Tutorial (link at top) duplicate your original storm cloud footage or photo and then go to Effects>Simulation>CC Mr. Mercury to apply this cool effect to that layer. Rename this layer “Debris”.
10) Here are my settings for “Debris” Now I also resized this debris field to be small and in proportion to the twister so you’ll need to do that too. I also added a mask with lots of feather.
11) Add a direction blur to the debris because it’s flying fast in circles and you want it to have a motion blur effect.
12) in addition to the debris field (not shown in the above photo), you should add a dirt or dust field which is just the same cloud footage duplicated again, and masked with a heavy feather. The debris and dust field need to have the same horizontal movement across the ground (same position keyframes) as the funnel.
Here (above) are my animation settings for the Funnel, Debris, and Dust.
That’s actually how easy it is. Again, the key is good footage. I’ve learned over a course of a couple years that it’s nearly impossible to get a realistic tornado going in 3D or 2D without some kind of actual storm footage. Maybe I’m wrong, maybe there is someone out there that has done it. But this is the way I found out how to do it with a deadline.
Additional Effects: Lightning (lightning effect in AE), rain/hail and water drops (see Water Drop tutorial by Video Copilot).
Thanks for viewing! I hope everyone can find this tutorial useful. I can’t supply the project file because of purchased footage, but I’m sure there’s some free storm footage out there somwhere (National Weather agency?)
For $75 “Real Clouds” is a great buy!