jittery tracks...


#1

Hi all…
any thoughts on how I can get my tracks from being jittery?
The footage is not very contrasty and tracking is tough at best and focus even gets a bit blurred at times.
Even with hand tracking, I’m never exact.
I’ve tried trackerviz but I’m still having problems.
I’ve heard there’s a way to average tracks (without using trackerviz) but I don’t know how…
Any thoughts would be helpful.

Thanks,
Joe


#2

Have you tried pre-comping your footage and boosting the contrast? Or making the image just black and white so you have distinct black and white areas?

As for averaging your tracks you could do that in Trackerviz. Is there a reason why you want to average them without doing it the Trackerviz way? Wouldn’t you be accomplishing the same thing?


#3

yes, you’re right…trackviz would (did) do the samething…but it just wasn’t helping a whole lot.
I’ll try to re-track with your suggestion…never tried it that way.
I did try an rgb track but same deal, although I didn’t boost anything, good suggestion.


#4

yeah, TrackerViz averages tracks just like any other script would. Averaging is averaging.

can you post any samples of the footage?


#5

what are you trying to track?

If procedural software can’t touch it, then hand-tracking will be much quicker. At the risk of patronising (sorry in advance), trace the curves of the track with a wacom at like half or quarter speed using the motion sketch tool. then you can fix issues on a case-by-case basis them with a judicious application of smooth().

Dan


#6

Hi all…
sorry for the delay…I can’t upload footage…I use .rar but it wants a different zip extention I guess. Here are some screenshot examples. I’m supposed to track her forehead to attach different horns (the director doesn’t like the current ones). What the the pics don’t really show is that at times, she’s leaning in super close to the camera and bending down and other times, she’ll move from that positon to a far away standing position…on top of it, the focus gets soft.
To be sure, there are times I can get a track on the current ‘horns’ but then the contrast goes soft.
I would certainly love to email someone a small bit of footage if you to take a crack at it.


#7

ok, so looking at those images and now understanding what the shot is a bit… I would say track it where you can, and then hand track it where you have to. That’ll just mean positioning the tracker by hand, going to the next frame, positioning it again, going to the next frame, etc… when you get somewhere you think it will track ok again, then just hit the forward button again. If it slips, you can also go back and fix the bad frames manually.

however, with as much perspective changing that is undoubtedly happening in this shot, I’m guessing the AE tracks will only be useful for removing (patching over) the horns that are currently there. To put some different ones on, the new ones are going to have to be changing perspective as well, to match her head, and for that, you’ll need 3D models of horns, and a 3D track. You might be able to get away with using 2D images of horns in AE, but you’ll have to be very clever about how and where you transition between different perspective images of the horns.


#8

Yes…obviously, the real footage is HD sized but the constraints of uploading footage makes me make them small pics.
But, I’ve been doing what you suggested. Pretty much the whole shot was hand tracked. I did use trackerviz on a few places but the rotational values kept getting off (maybe as a result of the constant changing perspectives). In the end, I would have to go in and adjust the points / curves manually. But even at that, a couple pixels off and it’s swimming a bit. I was trying to be slick when she changed her perspective by using a warp effect on the ‘new 2D horns’ but its still not good.
I’ll try a 3d Track and see if that helps. Sure wish they would’ve put markers on her head or just did makeup on set.
Anyways…thanks for your assistance.
J


#9

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