CAP 151 -
Introduction to Computer Animation
Lesson 2 - Advanced Animation (part 2)
This lesson continues the last chapter, introducing more features of the After Effects interface. Objectives important to
- Roving Keyframes
- Anchor Points
- Pan Behind
- Faux Motion
- Hold Keyframes
We begin this lesson with a continuation of Tutorial 3 in Lesson 2. This tutorial has introduced a new problem. The motion path you created last week has abrupt speed changes that would be better if they were smoothed out.
Tutorial Notes and Questions
Note: Exercises should be carried out in the classroom. You will not get very much out of them by just reading, nor will you learn what is required by just experimenting on your own. Each exercise is meant to cover specific content that you will be required to know.
Work through the exercises and turn in your answers to all questions below as part of the homework for this assignment.
Tutorial 3 (Float Like a Butterfly, part 2):
- Start After Effects. Load the project you saved at the end of page 47, Select the butterfly layer.
Change the Workspace to Standard. Go back into the Graph Editor. If necessary, follow the instructions to see the Speed Graph.
Note the features: this graph shows keyframes when speed changes in the animation. As before, we would like this one to be a smooth curve or series of curves not a series of stair steps.
- This step suggests trying to smooth out the curve by hand. It tells you to use the Easy Ease Out button on the first keyframe and Easy Ease In on the last keyframe. This is a good time to mention that Easy Ease In means make a smooth curve going into the keyframe it is applied to, and Easy Ease Out means to apply a smooth curve going out of the keyframe it is applied to.
As instructed, region select the rest of the keyframes, press Alt, and click any one of them to make them all smooth keyframes. Try adjusting them manually, reviewing your work with RAM Preview.
- In this step we learn the better method for smoothing the speed curve. Start by double-clicking the word Position.
Question 1: According to the text, what will that double-click accomplish?
Select Animation, Keyframe Interpolation. You should see a Roving dropdown; on it, select Rove Across Time.
RAM Preview to check the animation now.
The text informs us that this technique does not apply to the first and last keyframes. They keep their Bezier handles, which now affect the entire curve.
- This step shows another technique that may or may not apply to this animation. Double-click Position again. Select Animation, Keyframe Assistant.
Select Time-Reverse Keyframes to reverse the butterfly's course.
Save the project again.
The next section of the lesson takes us to the Graph Editor, and introduces several useful commands.
Tutorial 4 (Anchor Point 101):
- Open the indicated project if it is not still open. Choose the indicated file from the Sources folder. Learn the shortcut to add it to the current comp: Ctrl-/.
Use the mouse shortcut to open all the parameters: Alt-Click the arrow by the layer's name.
- The flower in this layer will be rotated and scaled, which presents a problem. The text explains that we would like it to scale from the bottom of its stem, as though it were growing. We would also like it to rotate on this point. It will do neither at the moment, because both animations use the Anchor Point as the motionless point from which they scale, and about which they rotate. The flower's Anchor Point is currently in its center. You will change that in a few steps. First, double-click the flower layer in the Timeline panel. This will open a view of the layer in a Layer panel. The Layer panel gives you a panel in which to modify a layer itself independently of the composition.
Move the panel as instructed so you can see the Layer panel and the Comp panel at the same time.
- Follow the instructions to access the Anchor Point Path property of the layer.
Move the Anchor Point in the Layer panel. Note, as the text explains, that the flower will move in the Comp panel. The text asks a question that it does not quite answer. You are not moving the flower. You are changing what part of the flower is attached to the anchor point. (Sorry, I'm tired of the pointless capitals.) The anchor point is staying in the same place in the Comp panel, so the flower moves in that panel as the anchor point is dragged/attached to a new part of the flower.
Think of the anchor point as a pin pushed through the middle of a picture, pinning the picture to the Comp panel. I want to move that pin to the bottom of the picture, but I can't pull the pin out of the Comp panel. The Layer panel lets the picture flow around the pin, so that the pin now goes through a different part of of the picture. In other words, you move the anchor point in the Layer panel, without moving it in the Comp panel. All motion is, after all, relative to your frame of reference.
- Since the flower is no longer located as desired in the Comp panel, fix it there.
- In case you didn't like the method above, the text shows you another way to move the anchor point.
Follow the instructions to turn on the Pan Behind tool. Using this tool, you can move the anchor point while in the Comp panel. Simpler?
- After moving the anchor point in the steps above, you had to move the layer (the flower) to the bottom side of the comp. This step gives you another way to do that.
If you right-click the Position value of the layer, you will be able to select Edit Value. Follow the instructions to set the position on the X and Y axes of the Comp panel.
The lesson continues with a technique that applies what some call the Ken Burns effect, zooming and panning on a still photo to give the illusion of animation. Watch some of the videos behind the link in the last sentence to get an idea of the value of this technique. It is not necessarily compelling in and of itself, but it is very effective when the narration accompanying the shot is about the feature that your zoom or pan is displaying.
Tutorial 5 (Faux Motion Control):
- Open the file indicated for this tutorial.
- Select the auto race layer and show its position and scale animations.
Question 2: What is the secret about showing a second or third animation timeline that is not needed for the first one you show?
Question 3: The text tells you to enable keyframing for position and scale. It does not say how. How do you do that?
- When you drag the layer for the first keyframe, then reduce the scale, you lose focus on the cars you meant to show. The problem is the location and function of the anchor point again.
- The same problem occurs when you try to set the still for the last keyframe. (You are being told to do it this way to show how irritating it is.)
- Start a new (although, already named) comp as instructed. Add the auto race image to it.
This time show the scale and anchor point features as instructed.
- Open the Layer panel for the auto race layer as instructed. Change magnification in this window so you can see all the cars.
As instructed, set the view in the Layer panel to Anchor Point Path. (Ken Burns, here we come.)
Drag the anchor point in the Layer panel. You will find you are also panning in the Comp panel.
- Pan to a new car, and change the scale as instructed. You will find you are zooming in the Comp panel.
- Keyframing should have created a motion path automatically in the Layer panel. Since there are only a few points on it, use the Bezier handles as instructed to smooth out the path.
Tutorial 6 (Hold Keyframes):
- The text is not clear in its instructions what it wants to accomplish, so play the QuickTime movie of the desired end result before beginning. Open the file indicated for this tutorial. The exercise will show us a new kind of keyframe, the Hold keyframe, and some new shortcuts as well.
- This step takes us back to needing to know how the timeline notations work. Review page 56 to get the details on four timeline notations. For this exercise, it is enough to know that the semi-colons in the notation used on page 54 tell us that this is Drop Frame notation (see last week's notes). In this short animation, we will not be concerned with hours or minutes. A number like 2;20 will mean the timeline point 2 seconds and 20 frames into the production.
Navigate to the timeline point indicated (1;00). Select the indicated layer and show Position, Scale, and Rotation keyframes.
- A new shortcut is presented: to move 10 frames earlier on the timeline, press Shift-PageUp. To move 10 frames later in the timeline, press Shift-PageDown. Use the first one, and change the parameters of the layer as indicated. Continue setting parameters at 0;10, 0;00, and the last frame in the layer.
- The animation moves the text on the screen, but the author wants it to be "harder-edged". Maybe this means "jerky"?
Select Position on the timeline to select all position keyframes. Since you want to select all the keyframes for Scale and Rotation as well, Shift-click those words as well.
Question 4: The text gives you a menu sequence to change the keyframe types. What is it?
This command changes the shape of the keyframes: diamond on the left side, square on the right side. This means come in as linear, but hold before exiting. This change affected all the keyframes. The authors did not want to change the ones at 1 second.
- When the authors tell you to make a "marquee selection", that is the same thing I mean when I say "region select". Drag an area over only the items you want to select.
Select all the keyframes at 1;00 using this method. Ctrl-click one of the keyframes you selected, and all three should change to plain linear keyframes.
- Now we turn to another effect that will sometimes be useful: blinking. Caution: use this sparingly. In the early days of the World Wide Web, it became very popular for a while, but we all got sick of it very quickly. Like any effect, use it only where it is appropriate.
Move back to 1;00 as instructed. Select the frame layer (the red rectangle image in the comp).
Question 5: Another command is used to make the frame layer start at this moment on the timeline. What is it?
Turn on the Opacity feature of the frame layer. (Review the hot keys back on page 19.) You automatically get a linear keyframe set at 100% opacity. (100% means it is not transparent.)
Toggle the keyframe to a hold keyframe by Ctrl-Alt-clicking it.
Move 10 frames ahead, and set the opacity to 0% (transparent). Since you started with a hold
keyframe, that's what you get this time.
One more new technique: select both of the new hold keyframes. Press Ctrl-C to copy them. Move ahead another 10 frames, and paste. You will paste two new hold keyframes, 10 frames apart. Finish the tutorial as instructed and preview it.
Assignment 4: The material for this week includes the next lesson. Carry out the tutorials on that note page to complete the classroom work for this week.