Motion tracker with fast moving object

BadWolf

Member Joined: Sep 10, 2015 09:45 Messages: 126 Offline

Solved by

Oct 19, 2020 07:24

I'm trying to understand the motion tracker tool. Filming soccer game, and I want it to track a particular player. Since the action is fast and the background varies (other players, etc) I'm having a very difficult time with motion tracker sticking to the object I select. It always loses focus pretty quickly. I've tried using a smaller selection. I don't want to go frame by frame if possible as that will take forever.

What I've been doing is selecting my player (making the selection area very small, like on a portion of their shirt or pants) and clicking the "Track" button. When the arrow loses focus, I then click stop, move the arrow back to the person, and click
"track" again to resume. I repeat this over and over.

Is that the right way to do it? I'm just not understanding how to accomplish what I want...I don't really understand the track tool very well.


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StevenG

Contributor Joined: Jan 14, 2014 14:04 Messages: 513 Offline

Oct 19, 2020 08:24

It could well be that there's too much motion, blur and similarity to nearby objects for the program to identify and follow the person automatically.

But tracking with the person by creating your own motion keyframes should be fairly simple and it will give you much more control in the process. Have you tried that?

BadWolf

Member Joined: Sep 10, 2015 09:45 Messages: 126 Offline

Oct 19, 2020 08:26

Quote It could well be that there's too much motion, blur and similarity to nearby objects for the program to identify and follow the person automatically.

But tracking with the person by creating your own motion keyframes should be fairly simple and it will give you much more control in the process. Have you tried that?

i haven't, that was going to be my next step if I couldn't get the "easy way" motion tracker tool to work the way I wanted.

optodata

Senior Contributor Location: California, USA Joined: Sep 16, 2011 16:04 Messages: 8630 Offline

Oct 19, 2020 14:11

Thanks for sharing those screenshots. It looks to me like you've chosen a poor target to track because the knee area of a running leg has no fixed shape, form or contrast for PD to lock onto. You'll have much better results by tracking the ball logo on the player's shirt.

You may also need to switch targets if the logo goes out of the frame, but as long as you can stick with a clear target like that you should be fine. Remember that you can do this in stages and even manually adjust the tracker if needed.

This message was edited 1 time. Last update was at Oct 20. 2020 12:26

Oliverz

Member Joined: Jul 01, 2020 07:32 Messages: 136 Offline

Oct 20, 2020 02:40

Quote .... creating your own motion keyframes .....

How do I create a motion keyframe? I'm only familiar with the motion tracker, which allows me to correct the focus frame by frame if necessary. Liebe Grüße / Regards
Oliver

StevenG

Contributor Joined: Jan 14, 2014 14:04 Messages: 513 Offline

Oct 20, 2020 08:09

This tutorial shows you how to blur a face as it moves around the screen, but the keyframing principles are the same.

Oliverz

Member Joined: Jul 01, 2020 07:32 Messages: 136 Offline

Oct 20, 2020 16:40

Thanks, but imho the MotionTracker is easier. Liebe Grüße / Regards
Oliver

StevenG

Contributor Joined: Jan 14, 2014 14:04 Messages: 513 Offline

Oct 20, 2020 21:20

Of course it is. But the problem with a fully automatic tool is that sometimes it doesn't do what you want it to do.

BadWolf

Member Joined: Sep 10, 2015 09:45 Messages: 126 Offline

Oct 21, 2020 07:00

Quote Thanks for sharing those screenshots. It looks to me like you've chosen a poor target to track because the knee area of a running leg has no fixed shape, form or contrast for PD to lock onto. You'll have much better results by tracking the ball logo on the player's shirt.

You may also need to switch targets if the logo goes out of the frame, but as long as you can stick with a clear target like that you should be fine. Remember that you can do this in stages and even manually adjust the tracker if needed.

Thanks so much for the advice about where to position the tracker. I've seen various topics on how large to have the tracker, etc. What you said makes sense!