OUGD202 - Software Workshop - After Effects [3]

3rd After Effects workshop looking primarily at Keyframe interpolation and importing content from Illustrator to create motion paths within After Effects. We also looked at layer masks which was particularly useful. (read more for content)

Keyframe interpolation

Dictionary definition: a message (spoken or written) that is introduced or inserted
In terms of After Effects: insert between fixed points

We have options to change the paths between they keyframes/achor points. Here I have added a 100px solid layer, added a position keyframe at the start of the timeline and added two more consecutive keyframes.

Similiarly to the 'Convert Achor Point' tool in Illustartor, you can alter the points inbetween two keyframes using the Pen tool in After Effects.

You can also use the 'Convert Vertex' tool to change a smooth, bezier curve to a straight anchor point. Simply by changing the interpolation, you can alter the animation quite dramatically.

Changing the keyframe interpolation

Temporal - Time

Spatial - Shape of the path

You can achieve the same result as the Convert Vectex tool by going to 'Animation > Keyframe Interpolation' and changing the 'Spatial Interpolation' from Bezier to Linear.

Hold Keyframes

Select all keyframes and either using the Animation menu or by right clicking on one of the keyframes and select 'Toggle hold keyframe'. Originally, the line between two keyframes showing the direction of the shape had several dots indicating the tweening frames inbetween two keyframes. This is interpolation. However, when toggling hold keyframes, this removes any interpolation - the shape simply appears at its indicated position at each keyframe. An example when this could be useful is when animating a clock hand.

Importing files

I then imported an Illustrator file containing the word, 'Blink'. As opposed to transforming the position, the opacity will be changed instead. As you can see, After Effects adds tweening frames so the word slowly transforms from 100% opacity to 0. In order to give the impression that the word is blinking, I selected the keyframes and selected 'Toggle hold keyframe'. 

I also altered the scale at various intervals and toggled these keyframes too. 

If you select all over the keyframes, you are then able to move them forward and backward in time. When holding the alt key, however, you are able to compress the keyframes. You still retain the same relative difference between these keyframes though the time it spans differs.

Roving

The default setting for keyframe (in terms of roving) is that it is positioned at a fixed point in time. You can change the keyframes so they 'rove' across time - it will position the keyframe/s relative to the first and last keyframe.

In this case, I set the middle keyframes to 'Rove Across Time'. The shape of the keyframe changes in the timeline window and rather than holding alt when selecting all keyframes to retain the relative spacing, you simply drag one of the keyframes to your desired position.

Using Illustrator Paths

When a position keyframe is activated/enabled, you can copy and paste a shape (or path) created in Illustrator over to After Effects which automatically creates a motion path. This is a quick and efficient way to create a path designed to your liking. The path is still editable, just like any other motion path created in After Effects.  

If you want the object to turn anticlockwise as opposed to clockwise (or vice versa) you can go to 'Animation > Keyframe Asssitant > Time-Reverse Keyframes.

You can also alter the orientation of the shape when following the path.

Layer masks 

Something which determines whether the layer (or parts of the layer) are transparent or opaque. A mask in After Effects is a vector shape which can by accessed simply by highlighting the layer (a solid shape set to the same size as the composition) and creating an ellipse (or any other shape) on the composition.

You can change the properties of the mask in the 'Masks' drop down menu in the layer panel. Using the selection tool, you can select the anchor points and change the shape of the mask.

Reveal

We then used layer masks to 'reveal' the word 'reveal' (video in later post)

Melt

They keyboard shortcut to go to the Mask path property window is 'M'. Here I have copied the path of the word, 'MELT' as a layer mask in After Effects.

If you have multiple layers selected, you can enable keyframes for all just by clicking the stopwatch icon on just one of the layers. Here I have just altered several of the anchor points to give the impression the text is physically melting.

Dots

In the following, we can use the text layer to specify what parts of the 'dots' layer we will see. This process is referred to as using a 'matte'.

In this case,  I have chosen Alpha Matte (transparency/masks) though there are options to select Luma Matte which is used primarily with photography and altering the brightness.

Clouds

The cloud image is purposely much larger in width than the composition so we can create an animation where the image moves from left to right (or vice versa) to give the impression the clouds are moving.

You can also apply a 'Alpha Matte' so the image is only revealed where the text is places. This creates an interesting aesthetic which could be applied to a range of ideas.