blend between... Show After-Effects offers some great functions to blend between two values. The main two are: What's great about those functions is that they offer very extensive functionality for advanced users, but also give you the option to keep things simple. Let's start with simple :) The BasicsTo blend between 2 items, we need three things: Comfortably enough, linear and ease expect you to give them exactly that. Let's have a look at some examples: Blend between two numbersLet's try to interpolate between two numbers. Apply this expression to a Rotation property.
We are asking linear() to give us the number that is exactly halfway (0.5) between 200, and 400. You guessed it, the result is 300! Using a Slider as the amountBecause t expects a number between
0 and 1, we can easily use a slider to control it.
Now we can use our slider to blend between 200 and 400: You might have noticed that
we are multiplying the slider value by 0.01. Now, why is that? Blend between two pointslinear and ease are powerful, as they can blend between arrays of numbers.
We are asking linear() to give us back a point that is halfway between [0,0] and [500,500]. The result is [250,250]. Blend Between Colorslinear and ease work on multi-dimensional arrays, which means we can interpolate between colors!
(Don't forget to Pickwhip to your slider like in the slider example above). What's cool about these kinds of rigs is that we converted a number (0 - 100) to a color ([x,x,x,x]). Remapping the range (advanced)linear() is very powerful right out of the box, but it also has some hidden superpowers. It works, but it works only when the current time is somewhere between 0 and 1. Then, we have 9 seconds of complete and utter nothingness. We can do it like so:
As it turns out, by squeezing two additional values in-between t and our items, we can define a range in which t will perform in. Now if we apply the following expression to our Rotation property:
Our transition between 0 and 360 degrees will occur as t progresses between 3 and 8 seconds. How cool is that? linear() vs ease()linear() lets you blend between two items an amount specified by the t
value.
linear result: ease result: Comparing the two, it's easy to see the difference. ease is biased and blends using a secret curve to simulate an easing effect. Can you keyframe an expression?Expressions and Keyframes
After you add an expression to a property, you can continue to add or edit keyframes for the property.
Why are expressions not working in After Effects?The expression may not work if you are running After Effects in a different language, or if you changed the names of the items (such as layers, effects, or other property groups).
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