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control 3D position to cam
Hello, I’m trying to create an expression so that a 3d layer moving in z always stays within the camera’s visible cone.
If I only move it in Z according to its starting position, it will disappear, but in this case I’d like it to always be visible, so I’d like to calculate the x and y positions so that it remains visible in the camera’s cone.
I hope this makes sense, otherwise I’ll draw a picture.
thanks
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5 Replies
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It’s a little ambiguous, so a picture would help.
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yes I suspected, here is an image
Basically, the photo that zooms in on the camera must be close to the 960×540 axis of the camera, which is in the center.
to calculate a displacement in x and y
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Are you animating the photos by moving them on their z axis?
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If that’s the situation, layer moving on z, camera not moving, a position expression like this might work:
p0 = valueAtTime(0);
d = length(value,p0);
v = normalize(thisComp.layer("Camera 1").position - p0);
p0 + v*d -
yes, I only animate the Z of the photos, but I have more than 200 photos, which is why I’m looking to automate the moving process.
in x position, the point must be close to the axis which is at 960
for example, if my layer is positioned at 662 pixels, it needs to get closer to the 960 value to remain on the camera axis
similarly, if y is at 842, it needs to approach the 540 value
the first image is with only the z and the 2nd is with x and y corrected by hand
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