T354 Week 13 - Spring 2008

Announcements/Reality Check:

• Your final project proposals are due Thursday of this week (4/10). A storyboard and/or script is due one week later (4/19)
• Our scheduled Final Exam time is 8 am, Tuesday, April 29
• We'll continue to cover AE for the next 2 weeks. We have a final quiz, which is cummulative. It will cover material from the first two quizzes (Use them to study) and the AE content we've covered since then.

Agenda:

• Turn in & review homework
• Shape layers
• AE Tips & Techniques
• Chromakeying in AE

Please place your homework in your week 13 folder.

Shape Layers (Meyer, Chapter 30)

The same tools used to make masks can make shapes. (This is a new feature in version 8) If you have no layer selected, they will make shapes.

Note that when this tool is selected, Options become visible on the right.

In addition the the Meyer chapter, take a look at: http://www.layersmagazine.com/shape-layers-after-effects.html

and there is a very good video tutorial at: http://library.creativecow.net/articles/rabinowitz_aharon/Shape_Layer_Intro.php

Experiment with making shap layers for 10-15 minutes. Try to play with the repeater function

In Class Exercise:

• Make a short animation that demonstrates some things you can do with shape layers. Make your composition as cool and stunning as you can (considering this is a 30 minute exercise).
• When you are finished, output a full-size movie (H.263, MP4, or DV)
• Make sure it's called shapes!
• Leave it in your Week 13 folder

AE Tips & Techniques

Animation Presets

AE now uses Adobe Bridge to let users browse and apply preset animation templates. As well you can also save an effect as a template and open it up later to apply to another layer.

To view and use animation presets:

• Select a layer in a comp to apply an effect (eg a plain old solid).
• Then, from under the Animation menu, select “Apply Animation Preset” or “Browse Presets".
• Note the different effects and categories (shapes, backgrounds, texture, text, etc.)
• Note: double clicking a preset applies it to a layer. To preview a preset, click only once.

How to Create a Glint Effect

• Make a tall solid layer, we'll call it "glint". (You might want to make it white or light yellow)
• Use a mask to feather the edges (try 20 to 40 pixels or so for SDTV).
• Rotate the glint so that it's diagonal and place it directly above the layer you want to have the effect.
• Make sure you can see your layer Modes and check the glint's "Preserve Transparency" checkbox. (Under the T in the Modes column)
• Using position keyframes animate the glint layer moving across the target layer.
• Experiment with the various Transfer Modes to get different effects.
• You typically will need to pre-compose the glint with the target layer.
• HINT: You may want to then add other effects (eg adding an edge stroke, glow, etc.) to get more magic mojo

Making footage loop through Interpret Footage command

Often we have a clip of something that, as a layer, we'd like to have loop multiple times. (A movie of a spinning globe, etc.) There's no need to copy the layer x number of times. Here's a better way to do this:

• Right click, or control click the footage item in the project window.
• Select "Interpret Footage" -> "Main" from the pop-up window. (Or press Command-F)
• Look at the bottom of the window that has opened. There should be a text field near the bottom where you can specify how many times it should loop.
• Change this value to something larger than 1 (eg 50)
• You should then be able to lengthen the layer in the layer window by pulling the end of the trim tab.

Thursday-----------

Keying in AE

In the AE pro bundle you will find several different types of color keys. Most people who use AE for bluescreen work rely on 3rd party keyers, (Ultimatte, Keylight, Boris, etc.) An excellent one (Keylight has been built into the CS3 release of AE. it is possible to get good keying out of AE's built-in keying tools- but the footage should be lit well and recorded into a codec with good color sampling.

(Review 4:1:1, 4:2:2, etc.)

We’re going to play with some of the different keyers in AE to get used to the different ways they work.

Garbage matte - Often when subjects are shot for chroma keying, there are areas not masked or covered by the blue or green screen material or paint. These are typically outside of the subject's area of motion. Because they aren't the uniform blue or green required for color keying, we use what's called a garbage matte to get rid of them. In AE it's easy to use the pen tool to make a mask that serves as a garbage matte.

Color Key

This is the basic color keyer in AE. It can work well if the footage was created in a 3D program with a highly uniform color background.
While it works well with really uniform color keying, it's hard to get some bluescreen footage to work, as it's not extremely uniform.
A little edge feather can conceal bad footage or lighting but will lose the fine details.

Luma key

Luma keys work on brightness (as opposed to color). They are good if shooting against a solid white or black background.

Linear Color Key

This is a more sophisticated color keyer with the interesting feature that you can use it more than once.

Mattes

The matte choler and simple choker let you modify the matte created by the key. This is a quick and dirty way to eliminate the fringing

Color Difference Key

This key will get you much closer, as its additive eyedropper tool allows you to more easily create a good matte. It might be overwhelming for those new to keying.

Color Range

This is frequently used for video work. It is simple to use and has an additive eyedropper tool.

Difference Matte

A difference matte compares one layer to another and then keys out the info that's "different." This is usually used with footage shot from stationary cameras, or from motion controlled (repeatable) rigs. Imagine you have two layers, one is a static shot of a room. Another layer has the same shot, but a subject walks in. Using a Difference Mattem we can key out the subject.
Note that with all of the keyers, you will likely need to add an effect to get rid of an unwanted color fringe. The maniuplating the Hue / Saturation helps. You can use AE's spill supresser and the simple choker to clean up nasty edges.

In-class Exercise (5-points)

CHeck out the on-line help, the book, or these tutorials:

• http://www.dailymotion.com/video/x1ipbx_tuto-after-effects-keying-keylight_tech
• http://library.creativecow.net/articles/onneweer_barend/keylight.php

There are two video clips in the Scratch / T354 / Keyme.

• Blue Dance.mov
• Blue screen.mov

Use the keying tools and the info in the tutorial to put these clips together against any background you choose.

Leave a full-sized movie (DV, H.264 or MPEG4) in your week 13 folder. Make sure it's called "bluescreen".

Homework:

• Read Meyer Chapter 35 (Expressions)
• 30 second animation (Your choice of message and objective- but it must have one.) Try to make something new or along a different theme as your past work.
• You must use at least 3 shape layers. Brownie points if you use a new technique you've learned in the last few weeks.
• Turn it in as a full-size (SDTV) in the form of a DV, H.264 or MPEG4 movie.

Don't forget that your Final Project storyboard and/or scripts are due next Thursday!

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