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TOPIC: Tracking confusion with CoreMelt TrackX

Tracking confusion with CoreMelt TrackX 12 Jan 2018 11:43 #93167

  • Suzero
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Is anyone familiar with TrackX who can point me in the right direction?
I have installed the 15-day trial and immediately have what (to me) appears to be quite a difficult tracking assignment.
I need to place photographs on each of the cards this man is showing and throwing away.
I have been reading the help files for TrackX and and using the Track Layer generator.
Is that even the correct approach?

The tracking marks are sometimes obscured by his finger.
I don't mind manually keyframing the beginning and end because they are so fast and blurry in regard to tracking points, but when I adjust the Surface points, the whole tracking thing goes wonky in the middle too.
It is unclear to me if I should be dragging the yellow points or the blue ones.

All in all I am mighty confused.
Is this an advanced / difficult task in this case or am I just missing something?
Thanks for any help.

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Tracking confusion with CoreMelt TrackX 12 Jan 2018 12:15 #93169

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1- Have you watched the tutorial videos on how to do this?
vimeo.com/channels/coremelttrackx

2- Have you submitted a request for technical support from Coremelt?
support.coremelt.com/hc/en-gb/requests/new

I use TrackX often and find it very easy to use and very accurate.
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Tracking confusion with CoreMelt TrackX 12 Jan 2018 12:18 #93170

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Incidentally, TrackX is causing my FCPX to hang A LOT.
Anyone else having similar issues?

FCPX 10.4
Mac OS 10.12.6
16GB RAM
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Tracking confusion with CoreMelt TrackX 12 Jan 2018 12:55 #93177

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Nope, works fine for me. Again, did you report this to Coremelt tech support?

You do need to update to the latest versions for FCPX 10.4. Have y'all installed the latest versions?
Last Edit: 12 Jan 2018 12:56 by FCPX.guru.
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Tracking confusion with CoreMelt TrackX 13 Jan 2018 04:54 #93225

Suzero wrote:
… Is this an advanced / difficult task in this case or am I just missing something?…

… sorry to say, but don't you overestimate what a tracker can accomplish?

trackingpoints.jpg


good idea with the tracker-marks, but a 1/30th (or whatever) slow shutter speed make vanishing those., instantly.

plus, even when you match an overlay manually (painstaking but an option), it needs the same amount of blur to match the scene … hmmm?

guess, step 1: reshoot, much faster shutter speed, 1/500th, 1/1000th

sidenote trivia:
1965 (half a century ago!!), single take … awesome…
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Tracking confusion with CoreMelt TrackX 13 Jan 2018 08:07 #93228

ok, to correct myself:
when you apply a hefty dose of Motion Blur In Motion, it works. or at last, it mostly hides the fake.

But Motions 4-corner tracker asks for some manual adjustments … insert 'hovers' …
see attached clip… Again: too much natural motion blur to allow the tracker to 'catch' the marks.....
Attachments:
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Tracking confusion with CoreMelt TrackX 13 Jan 2018 11:45 #93231

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Hi Suzanna,

As Karsten wrote: this is indeed a very difficult task for the tracker.
Coremelt is using the Mocha tracker in their TrackX plugin. This is a planar tracker and it will use all the pixel information in the tracking region to track the movement of an object.
Since there are only 4 tiny crosshairs on the white cards that almost completely disappear in the fast movement, there is not much information left to track.
I would also suggest a reshoot and you could consider to use cards in alternating blue and green with several high contrast beefy tracking markers in the middle and in each corner of each card. The alternating colors will allow the tracker to easily differentiate between the cards. Now they are all white, but green and blue cards will make it easier for the tracker to "see" individual cards and as a bonus (especially when the hand is grabbing the card) it will help you to chromakey out the hand, instead of masking.
Reducing the camera's shutterspeed to 1/100 or 90 degrees will help. Shorter is also possible but it will introduce a bit more strobing (like in Saving Private Ryan).
In the TrackX plugin it is possible to increase the accuracy of the tracker to High and you can click a checkbock to let it render the appropriate amount of motionblur (180 degrees for a 1/50th shutterspeed (at 25p) or 90 degrees for 1/100th shutterspeed. You can acces these settings when you click on the "Tracking Options" button, on the right side from the "Track Forward" button.
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Tracking confusion with CoreMelt TrackX 13 Jan 2018 11:57 #93233

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Dylan was indeed the inspiration :-)
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Tracking confusion with CoreMelt TrackX 13 Jan 2018 16:04 #93239

… Dylan was indeed the inspiration

… a classic! ;)

Robbert gave an important hint:
TrackX works different than Motion's tracker, planar vs. marks.
For Motion, the tiny makers are a superb reference - as long as they are visible (blur, finger, out of frame,…)
TrackX uses the whole paper if you mark it as track-area - so, in this case, the motion blur and the 'bending' makes it even more difficult for the tracker to … track.

I dare to say, you can not avoid a reshoot; when tracking is done, you can apply motion-blur over the whole thing, you find a free plugin (<cough> form me) in our depository …
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Tracking confusion with CoreMelt TrackX 13 Jan 2018 16:50 #93245

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I know this is a really stupid idea, but what the hell; why not just print out the placards and film them for real, and forget the PITA that tracking can be?
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Tracking confusion with CoreMelt TrackX 14 Jan 2018 09:33 #93266

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Thanks for all the replies and advice, people.

A reshoot is not an option, but as I felt this might be a problem to track we also shot a version where I wil just superimpose the photos to one side of the frame. A completely different approach, but now, for a future Dylan-esque placard-throwing scene I have some useful tips for the shoot to make successful tracking more of a possibility :-)

Thanks again!
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Tracking confusion with CoreMelt TrackX 14 Jan 2018 09:34 #93267

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@FCPX.Guru: Not a stupid idea at all. Would have been a lot easier!
Alas, they didn't have the photos available yet during the shoot.
Last Edit: 14 Jan 2018 09:54 by Suzero.
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Tracking confusion with CoreMelt TrackX 14 Jan 2018 10:06 #93268

Suzero wrote:
… A completely different approach, …

What about the middle?
Make it a slideshow, export stills from the video and apply the new content…

cardz.jpg


depends on context and 'speed', could give a 'video-esk' impression…
just an idea…
Last Edit: 14 Jan 2018 10:07 by Karsten Schlüter.
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