Week 09

Week 08 – Topics

Due: Typography in Motion project
Mattes, masks and stencils
Alpha Track Matte
Nesting a track matte composite
Luma Track Matte
Animating matte layers
Stencil Alpha and Stencil Luma
Effects with track mattes and stencils

Week 08 – Assignments

1) Complete the exercises from Lesson 4 – Creating Transparency that we did not cover in class from last week.
Page 98   How Mask Paths Interpolate
Page 99   Mask Paths and Effects
Page 100   Multiple Mask Madness
Page 102   RotoBezier Mask Paths

Using your own design files, please complete the following Comps and have them ready to upload to my dropbox next week:

  • 03-Interpolation*starter
  • 04-Effects*starter
  • 05-Mask Modes*starter
  • 07-RotoBezier*starter

2) Reading for next week from AEA book – Lesson 8 – 3D Space

Your “Typography in Motion” project and the storyboard are due Tuesday, April 19 (Week 09). Be sure to have your project file ready to show in class.
Project specification:

  • Dimensions: 640 pixels x 480 pixels or you can use 720 pixels x 480 pixels
  • Length: 30 seconds or less.
  • Render the file as a QuickTime (.mov) file. This .mov file is the file you will copy to my dropbox.
  • You must add sound, feel free to use your own or use an audio file from the SMC sound library. On any SMC AET computer, click on the Finder to open a window. Click on the Globe icon with the question mark to connect to the server. You’ll see a disk marked SOUND LIBRARY.  These are audio files available for your use.

Helpful Dos and Don’ts

  • If a layer is created using vectors – such as Illustrator artwork – you can enable its Continuously Rasterize switch so that it remains sharp.

  • Use the Keyframe Assistant to add Easy Ease in (or Easy Ease out) to create more professional looking motion in your animations.
  • If you are having trouble Previewing your work, decrease your Resolution/Down Sample Factor from 100% to 50%.
  • Your design files should be RGB not CMYK.
  • Manually animating text in After Effects is complex … make use of the Text Animation Presets!
  • Remember that the objective of this assignment is for you ro demonstrate your understanding of the things we’ve covered in this class over the past six weeks: keyframing, basic animation, animation and text pre-sets, trimming layers, working with Text, working with shapes, rendering.
  • Pay attention to your file structure… remember you are linking your files to your .aep file so if you move it, you need to re-link it. Also, don’t work off of your Flash drive. Copy your files to your hard drive, always!
  • Be careful about the dimensions of your comp! Be sure you’re not creating a comp that is bigger than 720 x 480.  (Check it to make sure it’s not 4300 x 3200px or something equally too large!!)
  • To output sound make sure you have enabled your audio output. From the render queue, look for the Output Module, click on  “Lossless.” This will open the Output Module Settings. Check the box for Audio Output.
Importing Photoshop and Illustrator files

After Effects can import Photoshop and Illustrator files several different ways:

  • flattened into a single image (Footage: Merged)
  • selecting just a single layer to bring in (Footage: Choose layer)
  • as a composition where all of the layers exist as their own footage items which you can then animate. (Composition: Retain Layers)
Editing Photoshop Text layers

Import PSD as a Compostion with Retain layers>  Select Editable layers
Select a layer with Text and from Layer > Convert t0 Editable Text

Lesson 4 – Creating Transparency

Adding your own transparent areas to an image using masks, track mattes, and stencils.

Masking is a way to cut out sections of a specific layer.

A mask path says “I want to see only the area inside this shape; make the area outside transparent.”

You can draw your own shapes and paths directly on the layer, or copy paths from the Adobe companion programs Photoshop and Illustrator and paste them onto an After Effects layer to create a mask path.

Track mattes, by contrast, involve the combination of two layers. One layer – the matte – is used just to define transparency; you don’t directly see the image it contains. This matte is then used to decide what portions of the layer immediately below it are visible.

There are two types of mattes:
1. alpha mattes, which use the matte’s alpha channel to define the transparency of the second layer
2. luminance (or luma) mattes, which use the luminance – grayscale values, or brightness – of the matte layer to define the transparency of the second layer.

Stencils take the concept of track mattes further: Rather than define the transparency of the next layer below, a stencil layer defines the transparency of all the layers below, cutting a hole through the entire layer stack. Just like mattes, stencils can also be based around alpha channels or luminance.


  • Masks involve one layer
  • Mattes involve two layers (the fill and the matte)
  • Stencils are basically mattes that can affect multiple layers below them.
Page 104   Alpha Track Matte

Open Comps > 08a-Alpha Matte*starter.

The matte layer must be on top of the “fill” layer.

  • In the Project panel, open the Sources folder and select VirtualInsanity.mov – this will be the fill. Type Command + / to add it to your comp.
  • Then select Sources > Night Vision.ai, and either drag it into the Comp panel and position it, or type Command + / to add it centered in your comp. This text will be your matte.

Make sure the Modes column is visible in the Timeline panel.
For the VirtualInsanity.mov layer, click on the popup menu under the “TrkMat” heading: It will give you four choices for the type of matte, all of which should mention Night Vision.ai (the name of the layer above). Select Alpha Matte, which says use the alpha channel of the layer above for the matte.

After setting the Track Matte popup, the matte layer on top will have its
Video switch (the eyeball) turned off, and new icons will appear to the left of the layer names indicating that one is being used as a matte for the other. Notice there is no track matte popup for layer 1 because there is no layer above it. If there were additional layers above Night Vision.ai, the track matte popup would appear for the matte layer as well, which can be a source of confusion.

To understand the difference between Alpha and Alpha Inverted, go ahead and set the Track Matte (TrkMat) popup to Alpha Inverted Matte: Now the area inside the text will be transparent, and the area outside will be filled with the VirtualInsanity.mov layer. Set the popup back to Alpha Matte when you’re done.

Page 106   nesting a track matte composite

Open Comps > 08b-NightVision*starter.

To nest your track matte pair into this new comp, locate 08a-Alpha Matte*starter in the Project panel, and either drag it on top of 08b-Night-
in the Project panel

After you’ve “nested” the comp, you will see the name of your first composition 08a-Alpha Matte*starter appear as a layer in the second comp, with a special “comp” icon to reinforce this.


In the Timeline, slide the 08a-AlphaMatte*starter layer bar to the right to start around 00:28, which happens to line up with a good beat in the music.

The fill movie in 08a-AlphaMatte*starter contains flashy red-orange colors against black. Go to 03:16 in time; the black doesn’t read very well against the dark city footage. To quickly fix that, apply Effect > Channel > Invert to this nested comp layer. Now the black areas become white, and the red-orange areas become blue (the opposite color on the RGB color wheel).
Go to 01:13 in time; the turquoise text needs some color coordination help!
With the layer still selected, apply Effect > Color Correction > Hue/Saturation, and dial the Master Hue to somewhere between 50 and 90 degrees. This will shift the cool blue color to the warmer purple range.

The masked city footage has drop shadows to set it off from the purple background; you can do the same to your title here. Experiment with different layer styles:
Layer > Layer Styles > Drop Shadow will make the title appear to float above the city footage;
Layer Styles > Inner Shadow will make the title appear to be cut out from the city footage.
If you chose Drop Shadow, add Layer Styles > Bevel and Emboss to add more dimension;
if you chose Inner Shadow, add Layer Styles > Inner Glow to add contrast to the cut-out title.
In either case, experiment with their parameters to go beyond the default look.

As we mentioned, an advantage of nesting a composition is that you can treat its results as one layer, making animation easier. Go ahead and animate the 08a-Alpha Matte*starter layer to come on in an interesting fashion.

If the layer is moving quickly, turning on the Motion Blur switch for the layer plus the Timeline’s Enable Motion Blur switch will give a nice look.

Page 108 Luma Track Matte

Comps > 09-Luma Matte*starter.

As you learned in the previous exercise, track mattes require two layers, with the matte on top and the “fill” underneath:

  • In the Project panel’s Sources folder, select Firestorm.mov and add this to your comp. This will be your fill layer.
  • In the same folder is Cloud matte.mov; this will be your matte. Add it to your comp on top of Firestorm.mov. Scrub the current time indicator; you will see the Cloud matte.mov spew out a white cloudy stream over a black background.

Make Modes column visible.
Set the TrkMat popup for Firestorm.mov (remember – always the bottom layer of the two!) to Luma Matte. The matte layer will turn off, track matte icons will appear in the Timeline panel next to the layer names, and the fire will now play inside the cloudy stream. If you like, click on the Toggle Transparency Grid button to confirm that the black area outside the clouds is transparent.

As we noted earlier, you can edit the two components of a track matte independently from each other. For example, press H: You won’t see the fire,
because the luma matte layer is all black at its first frame. Slide the luma matte layer Cloud matte.mov to start earlier in time (before 00:00), and you will see some of the fire from the first frame of your comp.

To help confirm what the different matte modes do, select Luma Inverted Matte; now the fire plays outside the clouds.

Then select Alpha Matte: The fire plays full frame, ignoring the clouds. This is because Firestorm.mov is using the alpha channel of the full-frame movie Cloud matte.mov above it, and its alpha channel is all white

Page 109   animating matte layers

Open Comps > 10-Animated Matte*starter.

It is currently empty, with its Background Color set to black.

In the Project panel’s Sources folder, locate the still image inkblot matte.psd and add it to your comp.
We created inkblot matte.psd larger than the comp so you would have some room to animate it:

  • Type pto reveal Position, and click on its stopwatch to enable keyframing.
  • Slide it downward until the top of inkblot matte.psd just reaches the top of the comp. Remember you can hold Swhile dragging to constrain your movement in the Comp view, or scrub just the Y Position value (the second one) in the Timeline.
  • Press N, and slide the blot upward until its bottom just touches the bottom of the comp view.

With inkblot matte.psd selected, apply Effect > Distort > Turbulent Displace.
In the Effect Controls panel that opens, scrub its value for Evolution: The blot will now undulate in an organic manner.
This effect does not self-animate, but it’s easy enough to keyframe:

  • Press Hto return to 00:00. Reset Evolution to 0x +0.0° and click on the stopwatch for Evolution to enable keyframing.
  • Press N, and set Evolution to a different value, such as 1x +0.0° (one full revolution).


Bring the Project panel back forward, locate Firestorm.mov (your fill layer) in the Sources folder, and add it to the Timeline below inkblot matte.psd.
Check that Firestorm.mov starts at the beginning of your comp.

Make sure the Modes column is visible, and set the TrkMat popup for Firestorm.mov to Luma Matte. The fire will now play inside the animated
track matte. Note that just the shape of the matte – not the fire footage – is distorted by Turbulent Displace, which reminds us of the flexibility of mattes.

Page 110   Stencil Alpha and Stencil Luma

Open Comps > 11-Stencil Luma*starter.

It contains a pair of movies we’ve used earlier in this lesson, with a twist: Cityscape.mov has been inverted to make it look more graphical, and VirtualInsanity.mov has been applied on top of it in Overlay mode (you played with Blending Modes in the previous lesson).

In the Project panel’s Sources folder, select Cloud matte.mov and add it to the top of the layer stack. Move the current time indicator a bit later to where the cloud stream emerges, or drag Cloud matte.mov to start a second or two earlier so you see some action at the beginning of the comp.

In the Modes column, set the Mode popup for Cloud matte.mov to Stencil Luma – it’s near the bottom of the list. Just as in a
previous exercise, the image will appear only inside the clouds.
Note that unlike mattes, the Video switch for the stencil layer must stay on.

Just for fun, also try the Silhouette Luma option; the area outside the cloud stream will now be visible. Continuing the matte analogies, you can think of Silhouette as being “stencil inverted.”

Remember that stencils affect only the layers below them; not above. Drag Cloud matte.mov down one space in the layer stack so that it sits between VirtualInsanity.mov and Cityscape.mov. The layer below – Cityscape – will be cut out by the cloud stream, but the layer above – VirtualInsanity – will now play full frame.

Stencil Alpha

Open Comps > 12-Stencil Alpha*starter.

The background layers are the same as in the previous exercise. Layer 1 – Night Lites.ai – is an Illustrator layer that you will use as a stencil. Because it is black, it won’t work as a Stencil Luma (black pixels = zero opacity), but it will work as a Stencil Alpha.

Set the Mode popup for Night Lites.ai to Stencil Alpha. The background layers will now be contained inside the stencil’s alpha channel. (Silhouette Alpha is akin to “inverted stencil alpha” and will yield the opposite result; stick with Stencil Alpha.)

Make sure Night Lites.ai is selected, and apply Effect > Distort > Turbulent Displace.
Animate the Evolution property from 0 at time 00:00 to a value of 1 revolution at the end of the comp. RAM Preview. If the title isn’t “oozing,” verify that you animated one whole revolution and not just one degree!

Just to make life more interesting, make the amount of ooze change over time:

Animate Turbulent Displace’s Amount to increase from 0 to, say, 25. While you’re at it, have fun experimenting with the options under the Displacement popup too.

Finish off your animation by animating the stencil to make it come on in a more interesting fashion. When you’re done, check out our version in Comps_Finished > 12-Stencil Alpha_final. You applied Turbulent Displace to the stencil layer, but we applied it to an Adjustment Layer (Lesson 3) so it would affect layers below. Move it below the stencil layer and it will distort the movies only, and not the stencil. Choices, choices!

Page 113 effects with track mattes and stencils

Comps_Finished > 08a-Alpha Matte_final, duplicate it (Edit > Duplicate), and then open the duplicate comp.

  • Try adding Effect > Perspective > Drop Shadow to VirtualInsanity.mov: You won’t see any change. This is because the effect is being applied to the rectangular movie layer before the track matte is composited.
  • Now try adding Drop Shadow to the Night Vision.ai layer and increase the Distance parameter. You may think you’re seeing a normal shadow, but RAM Preview and you will realize that the fill movie is playing inside the shadow. This is because a black drop shadow at 50% opacity is being applied to the matte layer before the track matte is composited. Since the fill layer is using the alpha channel of the layer above as a matte, it plays at 50% opacity inside the shadow.

There are a few potential solutions to this problem:

  • If all you need is a drop shadow applied to the result of a track matte, select the second layer in your track matte pair (the fill), and apply Layer > Layer Styles > Drop Shadow. Layer Styles render after the matte has been calculated
  • Composite the track matte or stencil in one comp, then nest this comp into another comp. The resulting layer will look like any other source with an alpha channel, meaning you can apply any effect or layer style you want, including Drop Shadow, Roughen Edges, and the like. (After you complete Lesson 6, you will also know how to use precomposing to achieve the same result.)
  • Composite the track matte or stencil in its own comp, and then apply an Adjustment Layer on top of these layers. You can now apply any effect you like to the Adjustment Layer, and it will affect the result of the track matte or stencil composite below. The one catch is, if you apply Layer Styles to the Adjustment Layer; they will be ignored because they are not “effects.”

If you add a drop shadow to individual layers of a track matte pair, you either won’t see the result, or the shadow will become part of the matte that the fill plays inside of (above). However, if you apply Layer > Layer Styles > Drop Shadow, the shadow will be calculated after the matte, giving the desired result.



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Instructor for Graphic Design 71