Notice that it starts near the right edge but ends up in the lower left corner - exactly where the blue dot starts. Now examine the path traced out by the red dot. It starts in the lower left corner and ends up near the middle of the right edge after three seconds. If you examine the lower movie to the right you'll see such a path traced out by the blue dot. Visualize a graph showing the path that our layer traces out as it moves randomly from time zero through three seconds. Try different settings for a variety of results, keeping in mind what resolution you a working with because it naturally effects what settings you need for particular results.Īnd remember, if your layer is a 3D layer, you can use expressions for movement in 3D as well.Įxpressions for a layer attribute can also be used in conjunction with keyframes for that attribute, although you will need to turn the expression off when you set a keyframe, but you can then turn it back on again.Let's say we want to create a three-second loop of wiggle motion.
Of course the settings above are just a starting point. Try position.wiggle(5,10) for a film projector mis-registration effect or position.wiggle(50,50) for some violent camera shake > if you don’t want to see the edges of your layer and you don’t want to scale it beyond 100% don’t forget to render it out at a higher resolution before you comp it)įor added authenticity, you could also play around with expressions to get your artificial “hair in the gate” moving or make “fake film scratches” jump about. Try opacity.wiggle(10,50) for a faulty projector flicker effect, where 10 is frequency – changes per second, and 50 is the amplitude – the largest value the attribute will change. To add an expression, with the relevant layer attribute highlighted select:Įven if you are new to expressions and scripting, there is still a lot you can do, with some very basic in built expressions.įor example you can use the wiggle expression to randomly effect the values of various layer attributes for different effects: After Effects uses JavaScript 1.2 for expressions, so if you’re pretty handy with ActionScript or JavaScript or the like, there’s a lot you can do within After Effects. But what you cannot do with flash is to take an “Action-Scripted” animation and render it to use in broadcast or film – with After Effects you can. One of the primary strengths of Flash is its ability to use scripting to calculate variables and attribute values on the fly, which keeps file sizes down and interactivity to a maximum. While its implementation may not be as strong or as easy as using Action Script in Flash 5, it has one critical advantage. One of the most powerful and yet often under utilised additions to After Effects from version 5 onwards is the inclusion of expressions.
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