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The illusion of making a flag blow in the wind tends to be popular all the time. Here Kathlyn Lindeboom provides a quick tutorial on how to make this happen easily in After Effects using Forge FreeForm 2. The result is pretty cool and quite realistic as you'll see for yourself. .
Just wanted to demonstrate this technique using the flag that flies outside of the Creative COW Headquarters in Cambria, California.
Sure you could just grab your camera and shoot the flag and it's movement, and maybe that would be easier, but what if you didn't really have a flag? You could have one made. But what if the weather wasn't cooperating? You could use fans and all that other stuff, or you could create the flag in the computer and animate it using Forge FreeForm in Adobe After Effects. It's quick and simple.
I want to thank Chris Bobotis of Forge for his help in presenting this tutorial.
So, let's get started: Open After Effects and create a new project.
Step One: Preparing the Displacement Map:
Create a new comp of appropriate size and duration. Call it Displacement. For the purpose of this tutorial, I used 320x240, 10 sec long.
Import your cloud footage. I used a 256x256 tiff file that came as bonus files on the Forge FreeForm Disk, but you could just as easily create your own in Photoshop with the cloud filter.
Position the cloud footage in your Displacement comp at 192.0, 120.0.
Apply Effect>Offset.
Keyframe: Shift Center to:
0:00--0.0, 256.0
1:00--242.5, 13.5
1:03--0.0, 256.0
2:00--242.5, 13.5
2:03--0.0, 256.0 -- etc. You get the idea. Create a few, then copy and paste the rest.
Add a new solid, black and the size of the comp.
Apply Effect>Render>Ramp. Set start of ramp to 78.0, 120; color--black. Set the end of ramp at the right side of the comp window; color--white. Linear Ramp Shape. Position the ramp so that the black is positioned under where your flagpole will be.
Set your transfer mode to multiply.
Cloud footage.
This is what your comp should end up looking like
Step Two: Let's Wave our Flag!
Create a new comp. Same size and duration. Call it flag.
Add your Displacement Comp (from above.)
Add your flag and flagpole. I created my flagpole in After Effects with a solid and a couple of masks. The flag I did in Photoshop. You could create yours in AE, Illustrator, Photoshop or other appropriate graphics program.
Position your flagpole is over the black area of your displacement map. Position your flag so that it is attached to your flagpole (Note: the flag and flagpole need to be on separate layers.)
To the flag layer, apply Effect>Forge>FreeForm 2. Immediately you will notice that the flag image has changed. A light source and a slight effect of perspective has been added to the image. Notice also, that you now have 5 control points. These points (CP) are comprised of:
One control point (CP) at each corner (with Bezier like handles/tangents)
One CP in the middle of the image. This is represented by a small circle with 2 crosses in the middle.
These are the controls that you use for the majority of your flag movement.
Now, reposition the upper corners of your flag so that it is flag-shaped again and reattach it to the flagpole on the left side. You might even add a bit of curve the way I did.
Go to the TimeLine Window. Select the flag layer and hit the E key to show the effect contols. Now twirl open the arrow for FreeForm 2.
Twirl open the arrow for Number of Control Points. There you will see CP Values. Turn on the stopwatch. We'll set our keyframes later.
Twirl open the arrow for Object Numeric controls. Set the Object X Rotation to -40.0 degrees, and the Object Y Rotation to -15.0 degrees. You may need to adjust the Obj Y Rotation to keep the flag attached to the flagpole. (After you keyframe your movement, and do a ram preview, if the flag bounces off of the flagpole, reset the Object Y Rotation to something less.)
In your Effect Control Window, twirl open the arrow for Displacement Control. Set the Displace Layer to your displacement comp.
Leave Preview at Preview, set your antialias to none until you've set all of your CPs and are ready to render your movie.
Now, making sure that FreeForm 2 is highlighted in the Effects Window, advance through the timeline and reposition the CP tangents on the right side of the flag only. Each movement will set a new keyframe. I changed the values at one second intervals. (For the sake of this tutorial, I did several and copied and pasted them . You may want to fine tune the adjustment for your flag.
Be sure and save your project several times during all of this.
Check your movement with a RAM preview.
When you like what you have, then you're ready to render your flag movie.
Now, turn off the visibility of your displacement layer, if you haven't already, by clicking on the "eye" for that layer.
In the Effect Control Window, change the Mesh Subdivision (Under Mesh controls) to something like 80. Change the Antialias to Medium or High.
In your output module: use Animation at "most spatial" quality, and change the channel to RGB + Alpha, premultiplied with black.
Step Three: The Final Comp
Create a new comp. Same size and duration of your others.
Add your background. I used some stock footage from ARTBEATS -- the Establishments Mixed Cuts series.
Add your flag movie.
To add realism to your final movie, you'll want to add some shadow. I used the Pinnacle Image Lounge Real Shadows plug-in for AE.
Render your movie with the appropriate settings.
Enjoy. Here's my movie:
If you don't have Forge FreeForm 2, download a demo from the Forge website. Like to discuss this article? Check out the Forge Freeform COW.
And thanks again to Chris Bobotis for all his help.