- December 22, 2018 at 11:11 pm
Hi, I want to replace the green line on this video with red rectangle box. How can I do it with After Effects?
- December 23, 2018 at 12:31 am
You could try motion tracking it with something like Mocha, but it might be faster just to keyframe it by hand.
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- December 23, 2018 at 1:43 am
Hi Ali. Do you just want to change the color or do you want to make a larger/different shape? To just change the color then use the Change To Color effect, use the From eyedropper to select the green and it will automatically change to red.
- December 23, 2018 at 7:21 am
Since there’s nothing else green in the footage, you should be able to extract the green only and “fatten” it to a rectangle (with minimax) then turn it red with a color or tint effect.
Senior Graphic Designer
- December 23, 2018 at 8:48 am
I have already tried motion tracking. But it needs manual adjustment when it turn to another page (green line is moving back to left of the screen). When I enlarge searching area, It took a lot of time to complete tracking. Is it possible to get tracking data with chorama key?
My goal is put the number (in this case it stands on the right side of the green line) red rectangle box. Maybe something visual with particular effects later. So I think I need tracking data somehow?
- December 24, 2018 at 10:22 am
Yes, in that case you will need to track the shape. And you’re pretty much stuck with having to adjust it manually when the line returns to the left edge.
Second, more complicated but more automated option:
For a faster automated tracking, you might want to try is making a comp that is just a bit taller than the height of the green line, then isolating green only with channel combiner or keylight or some such thing. Then fattening the line (with minimax) and rendering out at a lower resolution (like quarter resolution). Then you could motion track it with a very wide tracking area, but it should be 16 times faster at quarter resolution. Apply result to a null. Then you will have to copy the tracking results (i.e. the null) to your main comp and scale it up using a new null. Parent the tracking null to the new null, scale the new null to 400% and unparent.
Hard to say if that is going to be any faster, since there are more steps.
Senior Graphic Designer
- December 24, 2018 at 6:15 pm
Kalleheikki Kannisto thank you so much. Your solutions are very enlightening and eye opener for me. Maybe I must try something different with midi data. Maybe a project for scrooling music sheet. I don’t know, I will give it a chance. Thank you very much ????
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