Offset and Displace

CATEGORIES: After Effects, Tutorials | Steve Holmes | October 07, 2005

Creating an interesting title sequence can involve many different techniques. But here’s one simple trick that can be used for almost any type of project-Offset. Used in conjunction with the Displacement Map filter, it can also add much reality to a shot.

The specs for this project are an NTSC D1 composition at 720×486, 29.97 frames per second, at a length of 10 seconds. The Offset filter is in the Standard version of After Effects, but please note that the Displacement Map filter only ships with the Professional version, so maybe now is a good time to upgrade…?

STEP 1:

Start in Photoshop and create a new file at 72 dpi with a white background. Size is important here; to be able to use the Offset filter to create a looping, seamless animation of these clouds, the edge pixels must match. Applying the Clouds filter to a file size that’s a multiple of 128 pixels will be perfectly seamless, so set the file to 1024 pixels on both axes. Press D to check your colors default to black and white, then go to Filter>Render>Clouds. Save the file as a PSD to your drive and name it “Clouds_1024,” and then switch across to After Effects.

STEP 2:

Start with the composition open and double-click in the project window to access the Import dialog. Locate and import the Clouds_1024.psd file and then drag it into the Timeline. This layer is going to be the backmost moving cloud, so hit the S key to access its scale property and drop it down to around 65%. Now, go to the Effect menu and choose Distort>Offset. Making sure the Timeline is at 0 seconds (hit Home if not), go to the Effect Controls Window (ECW) and turn on a keyframe for the Shift Center To value.

STEP 3:

Move the Current Time Indicator (CTI) in the Timeline to the end of the animation, and change the Shift Center’s X value to 2000 pixels. Hitting the 0 key on the keypad for a RAM Preview now shows seamless clouds moving fast in the background. This would look more realistic with an image behind it, so import anything you would like to use as a backdrop and drag it into the Timeline (at 0 seconds) behind the clouds layer. Then go to the Modes section of the Switches/Modes, and set the clouds layer to use the Screen blend mode.

STEP 4:

Now we can add a logo that we wish to have blowing around in the foggy scene. Here, we’ve imported a vector logo we created quickly in Illustrator CS. Drag the logo to the top of the Timeline at 0 seconds, and then go to Effect>Distort>Displace. In the ECW for this layer, change the Displacement Map Layer to layer 2, the animated clouds. Set both the Use For options to Luminance, the Max Horizontal Displacement to 0, and the Max Vertical Displacement to around 20. Do a RAM Preview, and what have we got? Hmm…

STEP 5:

The problem with the Displacement Map function is that it can read the physical pixels of a layer, but if the layer is static and has effects applied to animate it, it doesn’t see the motion, only the static pixels. So we need to trick AE into thinking the offset clouds is rendered. Select the Clouds layer and hit Command-D (PC: Control-D) to duplicate it. Then, go to Layer>Pre-Compose, and in the dialog, make sure Move All Attributes Into the New Composition is selected (this ensures the Offset filter and keyframes are applied to the layer inside the comp), check Open New Composition, and click OK.

STEP 6:

Inside the new comp, select the clouds layer and set the Screen mode back to Normal. Because this motion is a little nearer the camera, let’s speed it up a little more. Go to the second Offset keyframe at 10 seconds and change the value to 3000 on the X axis. Switch back to the main composition (leaving the pre-comp open also), select the logo layer, and make sure that the clouds pre-comp (layer 2) is now selected as the Displacement Map Layer. Do a RAM Preview, and the logo is now animating very nicely indeed.

STEP 7:

Now at this point, you might feel that the displacement of the logo is a little too harsh, like the edges are being broken up a little too much. It would be nice to soften it up a bit. Well, this is the beauty of (1) pre-comps, (2) offsetting a Photoshop layer, and (3) After Effects! Go back to the pre-comp, select the clouds layer, and go to Effect>Blur & Sharpen>Gaussian Blur. In the ECW, change the Blurriness value to around 5 or 6 pixels. Switch back to the main comp and see the difference! Still animating, but with a less destructive feel.

STEP 8:

You should notice now that the pre-comp clouds are sitting behind the logo, covering the white fog and image we put behind. However, instead of just hiding them, let’s use them to our advantage—as shadows for the logo layer! In the Timeline, move the clouds pre-comp layer above the logo, and then change its blend mode to Multiply. This will remove all the white pixels and lay the darker ones down as shadows. Hit T on the keyboard to access the Opacity value, and drop it to somewhere around 65%, just to lighten the shadow effect slightly.

STEP 9:

Now select the logo layer, duplicate it (Command-D [PC: Control-D]), and move it above the multiplied clouds/shadow layer. In the Timeline, go to the Modes section, and for the clouds/shadow layer, change it to the first option, Alpha Matte. This will use the animated pixels from the logo layer below to mask out the rest of the shadow clouds. Preview now, and it’s looking pretty realistic. To add some depth of field, select the background photo layer in the composition and apply Gaussian Blur to around 10 pixels to pull the logo away from the background.

STEP 10:

Now, we’ll add another layer of fast-moving clouds right in front of the camera. Select the original clouds layer (4), duplicate it, and move it to the top of the layer order by pressing Shift-Command-] (PC: Shift-Control-]). At 10 seconds, change the Offset effect’s Shift Center value to 5000 pixels on the X axis. Also, change the scale of the layer back to 100%, and adjust the Opacity down to 85%. A final RAM Preview gives us a wonderful title animation. Feel free to layer more clouds into this scene, each moving at different speeds, and enjoy the finished effect!

Steve Holmes is the Creative Director of Energi Design in Sausalito, California, as well as the co-host of the Total Training for After Effects video training series, and host of others such as InDesign CS, Creative Suite 2 Workflow, and Digital Video Workflow. He lives in Sausalito, California, and can be reached at steve@clickenergi.com when he’s not out training in the mountains on his road bike.

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