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Multiple Instances of Motion Tracking???
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[Rhett Robinson] “…probably just a few minutes for each kid, depending on camera angle and where they are able to hide in the room”
I believe zygotesoup wrote that the class was 30 minutes long …?
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Right, a few minutes each kid… unless this is really supposed to be exact like what we usually track motion for, you should be able to scrub through the 30 minutes & grab the track in about 2 or 3 for each, maybe less. In some ways, depending on the perfection required, you may not even want to use a “real tracker”, but follow them manually. I guess it depends on the purpose of the tracker… if it’s supposed to carefully follow head bobs to relate to autism or other subtle movements, or just the child’s location in a room. You could do that by hand in a hurry, if you wanted to. (Yeah, I know… it always takes at least twice as long as you think it will) Still, about 3 kids in, you’re going to get the hang of it, or for that matter, you could just move 30 different dots at a given interval, like 1 minute, or 15 seconds.
It really does boil down to how perfect it needs to be. If they want to determine children’s hive-like behavior or lonerism, I don’t think much is required.
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[zygotesoup] “(thank god!… i mean thank creative cow!!!)”
There’s a difference?
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For a class of kindergarten kids (hyperactive little blighters that they are), you don’t need motion tracking. You need motion prevention (A.K.A. shackles).
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I’ll be sure to give that a try!
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[Rhett Robinson] “you should be able to scrub through the 30 minutes & grab the track in about 2 or 3 for each”
In a perfect world… unfortunately, I’m not aware of any of those =O
Your point about putting special hats on students is a decent one for a scientific study, but if you have special colored hats why would you need to track colored dots on them? Seems redundant.
Also, the larger your search/feature area is the longer your track will take, and this applies on an exponential scale.
I think you’re a little overconfident of AE’s tracker capabilities. Especially considering that students may be leaving the frame and coming back in. Having little control over the footage will also contribute to problems.
If the camera is locked down then I agree that the track should be relatively easier.
Darby Edelen
Designer
Left Coast Digital
Santa Cruz, CA -
Okay, so all I had readily available to me was a crowd scene that is just over 5 minutes long… people are pretty active, but probably not running all over the place like kids will, and a couple of people did leave/enter the field of view, and the camera wasn’t locked down, like I’d want to do it.
Anyway, again, it seems it would be important to know how “perfect” the track needs to be. As was mentioned, you try to follow an earring, it’ll never happen.
In some way this thread reminds me of several things I’ve seen lately… if the real answer is that someone doesn’t want to take on the challenge (and that’s okay to say, BTW), then don’t make it based on technical reasons that don’t exist.
I agree the hat idea seems almost redundant (but that’s part of the “perfect world” scenario; the kiddos would love to wear giant fuzzy colored Dr. Seuss hats, and it would absolutely make this easier!), and I thought that it might be a situation where the kid’s faces actually have to be blotted out.
Okay, after a few trials, I set this up for an easy win, admittedly… I took standard footage and set this up at 3 (yep, only 3) FPS to cut down on processing, and made 10 tracks in a hurry, and corrected the tracks. Admittedly… this is *not* the requested scope, I don’t know what the actual filming conditions would be, or even what the use of the footage is, and this end of the spectrum is definitely just hobby for me… my money’s not made in motion tracking, and I’m more intrigued by the 3D motion tracking (like PFHoe? WOW!), but I like to be well-rounded.
Anyway, I’m glad that the original victim escaped, and I can certainly appreciate the difficulty of this task, but if it’s a one-time, one-day thing, I don’t think it would be too onerous. Then again, I’ve done off the wall things, like making a 12 minute stop-motion video, manually masked every frame of 4 minutes of video (in ImageReady… how’s that for crazy?) stippled, made 3D things in AE that shouldn’t have been, and generally just enjoy solving a challenge of something like this. Of course, I think that an initial test run would be greatly preferred to “here’s the footage, give me the product”, as I usually learn a lot in the first hour or two that can’t be taught.
I’m going to assume there’s not an award for the most verbose post… but this one has to be close. I’m glad I tested this… I did learn quite a bit in the time spent.
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[Rhett Robinson] “if the real answer is that someone doesn’t want to take on the challenge (and that’s okay to say, BTW), then don’t make it based on technical reasons that don’t exist.”
I think you’re being way too hard on us. There are always technical reasons for doing something or not doing something, ALWAYS. The point is that sometimes something is so technically challenging (on no budget with no time) and gives such uninspiring results that it’s entirely pointless to take it on.
I wouldn’t say ‘give up’ so much as ‘try something else’ and ‘make it easier on yourself.’
[Rhett Robinson] “I’m glad I tested this… I did learn quite a bit in the time spent.”
Nobody said it wasn’t possible, just that it wasn’t worth the time and effort for the non-existent budget. I respect your drive to do dull tasks for the result you want, but most of us don’t have the luxury of the time and budget to do such things. For example, I am constantly creating roto’d walk cycles out of only 15-30 frames and looping it, because it’s faster and easier than rotoing a whole minute.
How long did it take you to create those tracks? At 3FPS you should multiply your time invested by 10 if the goal is real-time results.
Darby Edelen
Designer
Left Coast Digital
Santa Cruz, CA -
How is that not “real-time results”? Barring the need to replicate the children’s faces, I see no reason that video can’t be tracked at a lower FPS… when I changed it back to 29.97 it was fine. Of course, initially that took just as long, but resulted in fewer keyframes, so I did it again a different way, changing the video to be 25% of it’s original time, tracking, then exanding it back. Again, pretty good… not perfect, but pretty good, and that actually seems like a better solution than my initial idea.
I guess my comment about admitting if someone doesn’t want to do something if that’s the issue was reflective of the Tori Amos stuff from a few days ago… Admittedly, the footage is not very good. I think it’s aimed at the fans, so if you’re a fan and a video freak, maybe it’s good. If you’re a pro, and expect to work with pro material in the hopes of getting noticed in the music video market, that’s probably not the project for you. If it was, there’d be a whole lot more people doing entire projects on spec, and hoping they get chosen to be paid later. I am pretty sure that Sony is not going to post new video because a bunch of people are complaining about the quality, and I guess that was my only point – that complaining never did it for me, personally.
As far as the “commitment to dull tasks”, well, actually the stop-motion took forever, and after an initial learning period, really didn’t get any faster. I was able to dramatically speed up the masking in ImageReady, although I have, of course, learned better ways since. Admittedly, in real life, I have to do plenty of tasks I don’t want to do (like timecoding depositions), and although I’ve found ways to make them dramatically faster than I was taught, and I’ve got some ideas for more improvements, to do a “better than a computer” job, it takes a human touch, and that’s me.
I certainly don’t want to come across as a know-it-all jerk, because I’m not, and I don’t know it all, which is why I’m here on a regular basis, to soak more of it in. I see that you’re a regular contributor, and although I don’t know your background personally, I see that you try to offer solutions or suggestions where possible, and that is the reason I’m here; to learn from other’s questions, and I try to help when I can as well, but admittedly, I’m usually putting in long hours, like to actually play when I can, and occasionally, I like to spend time with a human that I’m not working with or for.
One of the many things I learned is that I’d like to be able to set up all 30 trackers at once, and let them all run (even at a heightened rate) and then correct individually as needed, but I don’t really see that happening with AE’s built-in tracker. Without testing Mocha or any other applications, I’d agree with the idea that a more dedicated tracking app would be preferable. If it’s a one-time task, AE would do fine, in my opinion.
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[Rhett Robinson] “How is that not “real-time results”? Barring the need to replicate the children’s faces, I see no reason that video can’t be tracked at a lower FPS… when I changed it back to 29.97 it was fine.”
I think I misunderstood your initial plan of lowering the FPS of the clip.
The tracker will look at every frame of the footage regardless of what frame rate it is conformed to, so that doesn’t slow things down (or save any time either).
And hand adjusting the track is a frame based process as well, so I apologize for incorrectly stating that it would take 10 times as long. It does depend entirely depend on how accurate your track needs to be.
I was under the impression that you were somehow skipping frames in your track, which would have given ‘real time’ results (I mispoke in my post) but not frame accurate tracking. As you imply, ‘accurate’ is the keyword.
However, I should reiterate that, unless you know a technique I don’t, the Motion Tracker will look at every frame of the footage regardless of how many FPS it’s conformed to or how much it is Time-Stretched, so I believe this is an unnecessary step.
Darby Edelen
Designer
Left Coast Digital
Santa Cruz, CA
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