Add the finishing touches to a TV bumper using Null objects and the Collapse Transformations switch in AE.
This lesson is the second in the two-part series of constructing a five-second bumper in Adobe After Effects. The first part of this tutorial can be seen here. In this lesson you will learn how to nest compositions, use a Null object to control camera movement between scenes, and gain a better understanding of the Collapse Transformations switch.
This lesson picks up where the masterclass in the previous issue leaves off, using elements you created in the last lesson. You should have two compositions named ‘Scene 1’ featuring the type “Coming Up”, and “Next” and ‘Scene 2’ that should have the type “Next”, with additional ink layers scattered throughout. All of the layers should be 3D layers. The relevant files are included on the cover CD for you to follow along with.
01 A composition placed inside other compositions is called a ‘nested’ composition (or sometimes a pre comp). There are many reasons to do this. In this case, breaking the animation into two compositions will simplify the management of the project.
Create a new standard definition composition called ‘Main’. Place comps Scene 1 and Scene 2 into ‘Main’. Then, click the 3D switch on both layers. Select the layer for Scene 2, and type ‘P’ to isolate the position property. Set the position of this layer to be 2,500, 300, 3,000 in X, Y & Z. Then press Shift-R to view the Rotation property and orient the layer 45-degrees in the Y axis.
02 Go to Layer>New Camera (default settings). At this point, hit the C key, or go to the tools and select the Orbit Camera tool. Move your mouse around a bit in the comp window. This will change the position of the camera, but not the point of interest. Notice how flat the Scene 1 appears to be, despite the fact the layers are in various locations in 3D space. This is how nested compositions behave, by default.
03 Click the Collapse Transformations Switch for both layers.
04 This switch ensures the 3D properties of the layers inside the composition will be retained. Now, orbit the camera around. You’ll see how the layers retain their 3D properties. In the images above, the top image shows before Collapse Transformations – the layers are flat and cropped.
The bottom image shows after Collapse Transformations – layers are uncropped and in 3D space. You can see multiple scenes could be nested into one main composition. This method keeps projects organized, and easy to manage.
05 Next, you’ll move a camera between the scenes. Use the Undo command to reset the camera to the original position, or delete it and create another camera. Hit the v key to access the Selection Tool. Create a Null by going to Layer>New>Null Object. By default, it will be called Null followed by an integer.
I prefer to rename the Null in accordance with how it is being used. With the Null selected, go to Layer>Solid Settings and name the Null to be called Camera Null. Make the Null a 3D layer. This is critical. A 3D camera cannot be controlled in a useful manner by a 2D Null. Make sure the Parent column is visible by right-clicking the Column header in the comp window, and selecting the Columns> Parent option.
06 Parent the Camera layer to ‘Camera Null’.
07 Now the Camera will do everything that the Null does: move, rotate, scale, etc. One thing I like about this is that it gives the user a convenient camera controller in the middle of the comp window.
Because the Camera is parented to the Null, the Null will not appear to move in the Active Camera view. Click-&-drag the Null, and the camera’s position and point of interest will follow.
Rotate the Null, the camera will rotate around the Null’s anchor point. Notice, however, that moving the Null will, most likely, feel a little odd at first. Dragging the Null to the right moves the camera to the right, which makes the objects in the scene move to the left.
08 We’ll now animate the camera. Select the Comps ‘Scene 1’ and ‘Scene 2’. Switch to the Top view, and zoom to 6.25 per cent. You’ll be able to select and see the positions of Scene 1 and Scene 2.
09 Select the Null, and hit p to show its position, and Shift-R to add Rotation. Place your Time Indicator at three seconds and create keyframes for position and Y rotation of Camera Null. Move to 4 seconds. Set the Null’s Y orientation to -45º and set its position to 2,500, 200, 300, just like Scene 2.
10 Switch back to the camera view to preview your animation. You can now see how it can be quite easy to divide scenes into compositions, nest them into one comp, and create camera moves between them. Using a Null makes camera movement between the nested comps much easier.
A special thanks to Andrew Kramer of videocopilot.net for providing images from his new Riot Gear collection, a collection of high-definition organic stock footage.
Controlling a camera with a null object
One of the most common questions I hear is: “How do I create smooth camera moves?” Understandably, After Effects cameras (by default) have both Position and a Point of Interest to manage, which can be difficult to keyframe smoothly and consistently.
How do the pros make those awesome camera moves while handling these properties? It’s very simple: they don’t deal with them at all! Instead of animating the camera’s properties, a common technique is to parent the camera to a Null object and animate the Null.
Nulls are, essentially, invisible objects. They have all the properties of other layers, but are never visible in the final render. When a camera is parented to a Null object, the position and point of interest move together.
Tip
Be aware of keyframe interpolation. If you want to be able to smooth the camera movements when necessary, click the keyframe while pressing the control key and choose Keyframe Interpolation. Choose bézier if you want to have a smoother movement. Adjust the keyframe on your timeline; choose linear if you want a more rigid movement.
WHO: Harry Frank stumbled into motion graphics as a starving musician. He lives in Detroit south of 8 Mile, earning a living as a designer, teacher, and rock star.
CONTACT: graymachine.com
SOFTWARE: Adobe After Effects
TIME TO COMPLETE: One hour
ON THE CD: All files for this tutorial can be found on the cover CD.