Keyframe interpolation using illustrator paths
- To interpolate: to insert between fixed points
- Looking at how to manage the terms between the key frame states
- Position: we see the line in which the layer is going to move in our composition window
- The default way after effects decides how the layer will move is a bezier curve, ending with an anchor point which enables you to change how the layer is going to move
- Tool palette in after effects -> pen tool -> vertex tool (rather than being called anchor points as in illustrator)
- Take the convert vertex tool and click on a point and it will change from being a smooth curve to a corner point. The spacial interpolation has now changed.
- Example of a mix of bezier curves and corner points
- Have to highlight one or more keyframes. Animation menu -> keyframe interpolation -> opens dialogue box with options to change the temporal interpolation (how things change over time) and the spacial interpolation. Gives further options.
- Quick way to add key frames: drag the red line to where you want the key frame and click the little diamond on the left of layer name.
- Select all of your key frames, go back to keyframe interpolation option and you can change the temporal interpolation keyframe so it becomes a 'hold' key frame. This means that we don't have any interpolation, so there is no change/movement between the key frames. We can see how it changes our motion path. (The more dots you have along a motion path the slower somethings going to move, the less dots the faster).
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- Key frames also take on different shapes according to the properties they have. The layer remains at the position until the next key frame, appearing to jump across the page. (Can right click key frames then change to toggle hold key frame.)
- This would be useful for animating the movement on a clock, with the hands jumping from second to second, or something flashing on and off.
Imported File: Blink Effect
- Working with other files: imported 'blink' file as footage. To make the text 'blink' creating new key frames and changing the opacity from 100 to 0 and back to 100 etc... Have to make sure you are clicked on to the opacity option and click the stopwatch next to it, to create a keyframe with the changed opacity. Click on the diamond for the frame you want to change the opacity for and it will be highlighted as yellow.
- To make whole sequence of events move faster/slower, select all of the keyframes, and hold the alt key and drag either the first or the last.
- To make the temporal change smooth between all key frames, either space the frames out equally
- Go back to keyframe interpolation menu, and this time change the roving option to 'rove across time'. The key frames will then space themselves out equally between the first and last key frame. They then change from diamonds to dots. Now have a smooth motion between the keyframes. If you move the first or last key frame then all the frames in between will move as well. Can only specify roving time for spacial properties.
Working with Illustrator
1 : Use illustrator artwork to create motion paths.
- Create a new document with the PAL D1/DV Widescreen video set up option
- Create a new composition on after effects. Create a solid layer square shape. Go to illustrator, create a vector shape, don't save the illustrator file, but copy the shape, and go back to after effects, activate the position property of the layer selected, and enable key framing (by clicking on stopwatch next to position), and edit and paste illustrator file.
- This is an easy way to get something to move in a perfect shape, such as with a circle
- The three middle key frames have become roving key frames
- Once you have the path in after effects you can still edit it.
- Layer -> Transform -> Auto-orient: now, the layer orients itself along the path. Another option for when using motion.
2 : Masks
- Layer masks allow you to select which parts are transparent
- Create a new composition, and create a new solid, this time, the solid will be the size of the composition (there is a button to press).
- With our layer selected, use the shape tool, and create an ellipse. We have now created a vector shape which is determining which parts of the layer are transparent and which are opaque, creating a layer mask.
- Expand mask options and there are four mask properties. Each property has a stopwatch option next to it, so you can animate the different properties.
:: Mask path: to do with shape
:: Mask feather: make an edge softer or harder
:: Mask opacity
:: Mask expansion: contracts/expands the visible part of the layer inside or outside of the mask
- Can select the mask and work with it as you would work with an illustrator shape, e.g. changing the shape. If you double click on a point you get a bounding box, so you can resize the whole thing or move it to a different place.
- If you click on the stopwatch next to mask path property, you can create new key frames, and then drag out the shape, so you can create a vector shape that can be animated. E.g:
- Can also use the pen tool while you have the layer selected to create a mask on that layer
Imported File: Wipe Effect
- Imported illustrator file 'reveal'. Go to rectangle tool, make sure layer is selected, and create a rectangle around word.
- Need two key frames: a start one and an end one. Alter the bounding box of the first one (need to be on arrow tool) so the word isn't showing. Then on the second one the word will be showing. E.g:
Imported File: Melt
- Opened illustrator file 'melt' on illustrator. Text has been turned in to outlines. Copy the characters.
- Create a new composition in after effects. Create a new solid layer which is the size of the composition. With the layer selected, paste the illustrator paths. The paths will automatically become masks. Each illustrator shape has a mask.
- Select all masks (m is the shortcut) and all the mask path properties will be shown.
- Select the stopwatch next to the mask path with all layers selected.
- You can then move to different moments in time and move along the letters and select individual points to edit by dragging the edges rather than clicking the points.
Imported File: Dots (Illustrator and Photoshop Files)
- Create a new composition on after effects and import files.
- Clipping - another way to work with transparency
- Click the toggle switches/modes option button, to change layer switches around, we are going to use the TrackMat option in the drop down menu for the photoshop layer, choose the type of matte
- Choose 'alpha matte option', shows only in the layer where there is opacity in the layer above
Imported File: Clouds (Illustrator and Photoshop Files)
- Create a new composition on after effects and import files.
- What we have here is a photoshop file that is much bigger than our composition. We want to animate the position.
- Create two key frames: a starting one and an ending one. Drag the photoshop file so that it starts at one side and finished at the other.
- Add the text layer, and use the same 'TrackMat alpha matte' option as above.
- Try with a white background for a different look.
