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Expression for position value…
A while ago I was given an expression, which , by the way guys worked wonders. The point of it was to stop a credit roll from jittering, and to destropy aliasing when we transfered the video to film … The Expression was
[value[0], Math.floor(value[1]}]
okay like I said worked wonders. Problem is my boss man is a number junkie and had me do it with out the expression, figgureing our math on the pixel rate was safficiant, to stop the jitter and aliasing… He was wrong, so I reaplied the expression… But now, even though it works, he wants me to break down exactly whatthe expression tells the computer how it works, the math of it … Like I said he is a very logical person and doens’t like knowing things work, with out knowing why or how. . . ? Which is a fine quality, except he is looking me to explain it, and I think he wasnts more then well you put it on the posistion value there and then it doesn’t jitter…
Anyone?
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6 Replies
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Short anwser:
it makes sure that the vertical co
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Thank you … alot.
As far as fasinating or mystifying deepends If I read it and hear my own voice in my head while reading it, I am mystified, if however I read it and hear Bill Nye the Science guy in my head ….Fasinating…
The world works in mysterious ways. Unless you Bill Nye then is all makes sence…
Thanks again.
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Hey my Boss asked me to post this question, about the expression, so I have…
I had worked out a method for doing credit rolls that was supposed to do what your expression does. I have been unable to make it work, using Illustrator and After Effects.
I first determine an appropriate artboard dimension for illustrator. The parameters are:
The length of time each credit is on screen as selected from the possibilities for each format. The example I have used here is an HD roll with a pixel rate of 5.0 pixels per frame.
The vertical dimension of the artboard is then set to a value of daration in frames multiplied by the pixel rate. In this example the pixel rate is 5.0 and the duration is 3036 frames yielding a vertical dimension of 15180 pixels for the artboard.
The horizontal dimension for the artboard is the format horizontal pixel size, in theis case, 1920 pixels.
The compositiopn is made to fit the artboard top to bottom and and horizontally within the title safe size of the format, 1536 pixels centered on the artboard.
The composition is then brought into After Effects for rasterization. The duration is right on, and the pixel rate looks like 5 pixels per frame, however, the charachters are anti-aliased differently each frame telling me that the pixel rate is slightly off. When the expression is applied to the project everything is OK.
What am I missing?
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hmm maybe I should post as a new post …
‘The wheel weaves’
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Are your position keyframes _exactly_ 15180 pixels apart and 3036 frames ?
perhaps nudging the last keyframe just one frame is the cure.What framerate are you working at ?
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we are working at a frame rate of 24 to out put to 35mm.
I have checked the key frames and they are exactly at those frames… ?
so ?I mean the expression does work now it is more of a matter of knowing what the program is thinking, or how…
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