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expressions
Hey, I need help with an expression I’m trying to do. I’m new to expressions and I know just enough about scripting that I know I need help. I’m trying to add a wiggle expression to a box I made. Now I understand the wiggles(freq,amp… part of it, but I don’t know what the rest of the equation (octives and ampMult and time) do.
I basically want the box to start shakeing at a certian point in time and become progressively more violent over a couple seconds. If someone could give me a good starting expression that I can talor that would be much appreciated. Thanks
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2 Replies
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I don’t think those other factors(the “mystery” ones nobody uses) will do what you want.
Dan had an earlier post that concerned wiggle then decay, here:
https://forums.creativecow.net/cgi-bin/new_read_post.cgi?forumid=2&postid=823392
But I think you’d be best tying either Amplitude or Frequency of the wiggle to a slider, then keyframing the slider. Zero as a keyframes kills the wiggle dead, a positive value down the line builds to the wiggle gradually.
In case you don’t know how:
wiggle (5,20)
highlight (select) the 5, then pickwhip to a slider stopwatch(Effect>Expression Controls>Slider Control) and you have an expression like this:
wiggle (effect(“Slider Control”)(“Slider”),20)
Setting keyframes with the slider now puts you in complete control.
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You shouldn’t worry too much about the other parameters. Nobody really uses them except for very, very rare occasions as there often are other ways of achieving the same result and if you wanted e.g. to slowdown footage and make it shake using wiggle, you’d pre-compose anyway. The octaves represent the number of overlapping sinus/ cosinus patterns of the underlying Perlin noise – the less octaves, the smoother you wiggle is. Amplitude multiplier and time do just what they say – you could feed alternative values e.g in time to make your wiggle slower or faster.
Mylenium
[Pour Myl
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