ccdc2
Level 1 (4 points)
Video

Q: Problem with Blur & Motion tracking in Motion 4

Hi all,

 

I need to blur out a license plate for a music video.  I duplicated the layer, added a square mask around the area I wanted blurred, and then added a gaussian blur and adjusted the strength & feathering.  I then recorded each keyframe, frame by frame, adjusting the mask to stay on the targeted blur area.

 

The problem I have is the blur doesn't stay on the targeted area and seemingly fades off when it gets close to the bottom of the frame.  I need it to stay on the targeted area and the blur follow it off the edge of the screen.  I have attached a link with said clip for reference to problem.

https://www.dropbox.com/s/g1lblb2qqvm2uvt/truckblur3.mov?dl=0

 

Any and all help appreciated.  Thank you in advance.

MacBook Pro with Retina display, OS X Mavericks (10.9.5)

Posted on Jul 12, 2016 6:59 AM

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Q: Problem with Blur & Motion tracking in Motion 4

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  • by GFXZen,Helpful

    GFXZen GFXZen Jul 12, 2016 5:51 PM in response to ccdc2
    Level 4 (1,643 points)
    Video
    Jul 12, 2016 5:51 PM in response to ccdc2

    When you have elements that go out of frame you will want to use the utilize the "offset track' option.  For your example, track the license until just before the tracking points go out of frame, then stop the track. Then enable the Offset Track option and reposition the tracker. You will want to pick something that is moving on the same axis, as close to the object's depth as you can.  In your shot, I'd avoid the chrome because that is going to warp the position of the tracking points.  I'd try using the "interstate" text on the car battery or part of the plastic tub just to the right.  

     

    Offset track is designed for situations like this, where  the object goes out of the frame, or where it might be temporary obscured by something else in the shot.  For more detail, take a look at the "Tracking Obscured or Off-Frame Points" section in the motion documentation.

    https://documentation.apple.com/en/motion/usermanual/#chapter=19%26section=14%26 hash=apple_ref:doc:uid:Motion-UserManual…