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Motion Tracker.... Can't get it to work.

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Michael Gyori
Motion Tracker.... Can't get it to work.
on Feb 6, 2011 at 2:47:36 am

I'm trying out the BCC7 motion tracker with the 14 day trial for Vegas Pro 10.

I can't get the motion tracker to work.

I set the cursor to the start of the video clip, reset the motion tracker, clear the render cache, enable track-on-the-fly, set the tracking position and size, and play the clip.

The tracking cursor correctly tracks for about 60 frames and then I get a message stating: Move the cursor to a previously tracked frame and click the Clear Render Cache button. Resume tracking from that point.

I do this.... but the same message is given at the same point. No matter how many times I do this, the result is the same. The image being tracked moves only a little from frame to frame and should be easy to track.

What am I doing wrong?


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John Rofrano
Re: Motion Tracker.... Can't get it to work.
on Feb 6, 2011 at 5:47:26 am

[Michael Gyori] "I set the cursor to the start of the video clip, reset the motion tracker, clear the render cache, enable track-on-the-fly, set the tracking position and size, and play the clip."
Instead of playing the clip, try using RAM Preview to track the clip. The problem with Vegas is that it will skip frames to keep the playback smooth but this messes up the motion tracker. Using Shift+B to RAM preview a selection ensures that Vegas serves every frame to the motion tracker.

I use this technique in my Boris TV episode:

Match Move in Sony Vegas Pro

~jr

http://www.johnrofrano.com
http://www.vasst.com



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Michael Gyori
Re: Motion Tracker.... Can't get it to work.
on Feb 8, 2011 at 3:59:01 am

Still doesn't work beyond a certain point. I don't think the cache is big enough to go longer than 14 seconds. I've increased it to the max of 5111mb with no effect.

This is really frustrating, as the whole reason I'm trying to track motion is so that I don't have to go through 13 minutes of video and track someone's moving face.

I'm using chromakeying. Unfortunately, the keyer is damaging my client's eye color. So I'm trying to track her face with a mask to keep her eyes their original color.

I guess I could break this up into about 60 15 second clips, but this almost defeats the whole purpose of using the motion tracker.

Even if I get this BBC Motion Key to track her face, how can I attach a mask to this motion. Isn't BCC Motion Key for removing objects? I just want to make a mask track a face.

Any suggestions how I can get the tracking to work on a clip longer than 14 seconds, and how I can attach this motion tracking to a mask?


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John Rofrano
Re: Motion Tracker.... Can't get it to work.
on Feb 8, 2011 at 5:14:19 pm

[Michael Gyori] "Still doesn't work beyond a certain point. I don't think the cache is big enough to go longer than 14 seconds. I've increased it to the max of 5111mb with no effect."
What you do is make a timeline loop for a small section that will fit into the RAM preview. Then when you get to the end of that, you move the selection forward and place your timeline cursor at the last tracked frame, press the Clear Render Cache button, and continue tracking. You should be able to track the entire timeline using this approach.

I don't believe there is any way to track a mask in Vegas though.

~jr

http://www.johnrofrano.com
http://www.vasst.com



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John Rofrano
Re: Motion Tracker.... Can't get it to work.
on Feb 9, 2011 at 12:28:37 am

In case you want to see how to restart after the tracker looses it's track, this happens to me in this Boris TV episode:






So you can see how I recover from it using the technique in my previous post.

~jr

http://www.johnrofrano.com
http://www.vasst.com



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Michael Gyori
Re: Motion Tracker.... Can't get it to work.
on Feb 11, 2011 at 7:03:39 pm

I'll have to try the method you list.... but if this can't help me track a mask, it's a mute point anyways.

This is surprising.... Vegas can't track a mask.

Do you know anyway I can solve this problem then:

I'm editing a green screen shoot. The Vegas Chromakeyer does a pretty job with the video (honestly better than the BCC Chromakeyer), but in order to get rid of the green, I lose some of the client's eye color. Right now I have to manually track her face with a mask through 13 minutes of video (a tedious process).

Can you recommend a way to avoid having to do this? Whenever I used the BCC Chromakeyer, I get terrible noise and shimmer in the clients hair.


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John Rofrano
Re: Motion Tracker.... Can't get it to work.
on Feb 11, 2011 at 7:26:55 pm

[Michael Gyori] "This is surprising.... Vegas can't track a mask. ...Do you know anyway I can solve this problem then."
I should have been more precise in my statement. What can't be tracked is the Pan/Crop Mask function but maybe I'm going about this the wrong way because you can also make a mask from any black and white media.

I'm not at my editing workstation so I can't test this, but I'm wondering if you can duplicate the chroma key track without the chroma key applied (to get the eye color back) and then use Motion Tracking on a piece of black and white generated media above that to be used as a mask with the track composite mode set to mask. That might work but as I said, I can't try it right now.

Do you understand what I'm getting at? (if not, i can try this later and perhaps explain it better)

~jr

http://www.johnrofrano.com
http://www.vasst.com



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John Rofrano
Re: Motion Tracker.... Can't get it to work.
on Feb 12, 2011 at 1:29:04 pm

Actually this does work but you have to precompose the mask. In a separate project, Use BCC Match Move to Motion Track the girls eye. Then create a Gradient Generated Media with white over her eyes and black everywhere else. Use this as the foreground media and you will have a moving mask. Now save that as a project and drop it into your original project and add the Sony Mask Generator and composite that over the chroma key footage and the unchroma keyed footage and it will punch a hole in the chroma key track to reveal the unprocessed eyes of the girl below it. So that's track (1) mask, track (2) chroma key, track (3) no chroma key.

~jr

http://www.johnrofrano.com
http://www.vasst.com



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Eric Müller
Re: Motion Tracker.... Can't get it to work.
on Mar 9, 2011 at 4:00:16 am

Actually I have the exact same Problem as Michael. Only difference: the machine I am using is old and less powerful. I allowed Vegas 1GB RAM to use. I am testing with a 18 seconds long clip and can only track 6 frames. After that, I have to... well, the deletion, re-adjusting the selection, start all over again. If I'd track every single frame by hand it probably would be faster.

Any new or other ideas why some people obviously can track only a few frames instead of a whole clip (even a really small one)?


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John Rofrano
Re: Motion Tracker.... Can't get it to work.
on Mar 9, 2011 at 4:59:02 am

It also depends on what you are trying to track, if there is enough contrast, how fast it is moving, and if you have allowed a large enough tracking box to follow it. If you can only get a few frames, adjust the tracking box and perhaps use the Motion Tracker Preprocess to add more contrast so the object is easier to track.

~jr

http://www.johnrofrano.com
http://www.vasst.com



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