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Motion Tracking footage that moves fast, and in different directions (Difficult problems) (Mac After Effects Cs5)
Hello people of CreativeCow, first off just like to say this website looks great and hope to get to know some people with great information.
I am currently editing a short film for myself, it is a war film and thus involves some effects. I decided to try my hand at blood splatters and being able to motion track items, such as wall hits, blood, posters etc to walls. Here is the problem i have tried to motion track the footage and when applying the track data to the null object problems seem to reveal themselves. I tried places a blood splatter and the blood moves and doesn’t look realistic, now i understand this is a common problem, however i feel because my footage moves fast and pans down thus leaving the initial track area that might be the problem?
I have tried many different ways but i cant seem to get the tracking to work, also as am working with the whole film edited without effects, i cut the part i wanted from the main clip yet it never takes the analysis from the cut? I have tried to read up on this but i never seem to find anything that is deals with my issues?
I do apologise if this has been asked before or am ignorant to other material/posts. If anyone could please aid me in anyway it would really be appreciated as i cant seem to get this right.Thank you very much
Andrew.
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7 Replies
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Use a trimmed clip from the original footage if possible. And try tracking in mocha instead. As you’ve discovered tracking is sometimes more art than science. And experience with a variety of techniques helps. Some shots require a combination of techniques, some shots are just impossible to track and are best done by hand,
Why don’t you post a clip of the shot in question and we might be able to offer more practicle advice.
online editor | colorist | VFX | BD author
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Hello Juan thank you for your reply, i will post up a clip asap.
for now ive taken some action shotsIt just seems like the tracking data has little to no effect
1st is the tracking point, i used rotation and postion while trying best to select to good points to track
Next you can see the postion after the start of the track data to then end (shows how much it moves)
Next i applied this data to a null object, then to a blood effect that i quickly positioned in 3D space and place on footage, after pick-whipping to the null object
Lastly this is shows the postion of how much the blood moves throughout the comp, like the tracking with the first two pictures.
More shots of how the blood moves, other pics dont show this as much
Hope this can just demonstrate the issues am having at the moment, really difficult even manually key-framing still seems to look like the blood is moving, any ideas guys?
Regards
Andrew
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That’s a largely uniform surface with very little tracking detail. It will be difficult to track. I would look into mochaAE which is bundled with after effects and may give you better results.
In the future on these sorts of shots, you’ll want to place some tracking markers in the frame. At least 4 but preferably more. You’ll then need to replace the markers, but that is easier than trying to track a blank wall.
online editor | colorist | VFX | BD author
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Hi again, Replace the markers? as in go through each frame and move it back to the spot where i originally placed them?
Also would you suggest a good mocha tutorial, that i learn from? specific to this problem?
Andy.
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Also there could be an issue with using 2d track data in 3d space here. You may be able to use an expression to transform the position. But I think a mocha corner pin track is your best choice.
online editor | colorist | VFX | BD author
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I see, would you suggest any place i can access information/guidance to learn this aspect of Mocha?
Cheers
Andy
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I would start learning mocha here:
https://www.imagineersystems.com/learn-mochaRoss Shain
Imagineer Systems
http://www.imagineersystems.com
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