Case Study: Elements of Motion Graphics

Alpha Channels

An alpha channel is a type of mask. The mask is called a Channel Mask, which changes the transparency of the edit.

Alpha channels define a selection in black, white, and varying shades of gray pixels. In other words, alpha channels store selections as 8-bit gray scale images.

You can create a mask by duplicating a colour channel and then editing the channel by using painting and editing tools and filters.

Examples:

57 seconds

https://www.youtube.com/watch?v=LeXgxN24loc

1. At the end title of the trailer the text is alpha channelled.

2. The cows around the drinks would also be channel masked in.

3. The drinks would have been masked into the image.

Key Frames

A key frame is a single still image in a sequence that happens at an important point in that sequence; key frames are put throughout a sequence to create points of motion. 

Examples:

1. An animation of a person walking, having key frames every time the legs move.

https://www.youtube.com/watch?v=u9y2tXnjP_E

at 4.36 key frames are used to make the legs walk.

2. Disney movies like Finding Nemo use key framing for their characters to move around. 

https://www.youtube.com/watch?v=aZ9nbv1VK0s

The fish swimming and the backgrounds moving is all key framed to make their movements happen.

3. An animation of an object changing its scale throughout the timeline is done through key framing. 

https://www.youtube.com/watch?v=yd8qQrVLfik

In this scene the puffer fish blows up and the scale is enlarged, this is done through key framing the scale.

3D Layers

Creating the illusion of depth in an image. Depth is where you have the X, Y & Z axis in after effects. It appears when you press the cube.

Examples:

1. 3D text is used with 3D layers by creating a text layer and pressing the cube option.

https://www.youtube.com/watch?v=z0-Gxik20As

 Between 4-5 seconds 3D layers are used on the ministry of sound logo.

2. 3D compositions are done to make a background look as if its in the distance.

https://www.youtube.com/watch?v=2hYGl8mw3zg

Between 1.45 and 1.47 3D compositions would have been done to make the background to create the illusion of depth in the image.

3. 3D animation also uses 3D layers to give depth in the image.

https://www.youtube.com/watch?v=rl9W9UBryKE

This video is an example of a short film with 3D animation to create depth.  

Layers

All compositions have layers so they can be edited easily.

There are different types of layers in a composition, which include, Video and audio layers that are based on footage items that you import, such as still images, movies, and audio tracks. These can be then broken down and edited easily singularly. 

Examples:

1. A layer can be used for Backgrounds

https://www.youtube.com/watch?v=DX1iplQQJTo

Between 6-7 seconds the layer of the Springfield sign is in the background making its layer below the others

2. A layer can be used for Foregrounds

https://www.youtube.com/watch?v=DX1iplQQJTo

Between 6-7 seconds the layer of the power plant is the main foreground making its layer above everything else

3. A layer can be used for People

https://www.youtube.com/watch?v=DX1iplQQJTo

Between 8-9 seconds the two characters from the simpsons are on a statue their layer will have to be placed accordingly to make them on top of the statue at the front of it so they're not at the back.