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Using a mask to create an image that's distortable

616 Views 9 Replies Latest reply: May 8, 2012 8:07 PM by nelso171 RSS
nelso171 Calculating status...
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Apr 13, 2012 5:51 PM

Essentially I'm trying to create a mask that captures the image it encircles and allows me to distort the image.  For example, if I have a picture of a person and draw a circle mask around the person's head, when I distort the mask it distorts (e.g. stretch/skew/bend) the person's head and not just the shape of the mask.  I'm trying to create my own version of this video but using Motion instead of AfterEffects and Mocha. 


If you watch the tutorial it's the AfterEffects "precompose" function that I'm trying to mimic.  And I don't think creating a new Group in motion is the ticket because I can only distort the image by adjusting the edge of the canvas vs. the edge of the mask. 


video's tutorial


Thanks for any and all help!  It's been a couple of frustrating days... 

Motion 5, Mac OS X (10.6.8)
  • Adam Scoffield Level 4 Level 4 (2,835 points)
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    Apr 15, 2012 6:04 AM (in response to nelso171)



    i think the only way you;re going to be able to get the corner pins in the right place is to export a still of the frame yo want, crop it and orientate to stand up straight, and then use that in Motion.


    However becuase of the process to set up the still, its probably never going to match the frame where you leap to full screen mode again. Also hand moving the frame in position be using the skew tools is probably not going to give you a great result. In the eample, although he hand animated the roto mask in Mocha he used its attach to planar before exporting so that it calculated all the skews and twists for him.


    You might want to look into the tracking tools in Motion, which can achieve a similar thing. Then applying a match move to the frame you want in the picture frame. You wouldnt need to export a still first in thhis case, you could just crop/mask the layer accordingly.





  • Adam Scoffield Level 4 Level 4 (2,835 points)
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    Apr 23, 2012 11:06 PM (in response to nelso171)



    the short answer is no. Because a mask is just that it masks the image. If you chnage the position of the mask its going to chnage what it is masking. This is absolutely the right way.


    I understand though what you want is the control points just around the area that is visible so you can distort it.

    This is not possible in Motion ( AFASIK) You can still distort the image or the layers its in using the distort tools, but they default the to size of the imge. Which is why I said export the image you want in the frame, cut it to size and import it again,  to that you dont need to mask it in Motion, then your adjustment handles will be in the right place.


    What you could try is to set the size of layer to fixed and to the size you want. Drop your masked image into it. Then you should get control handles in the right place.


    Is there any reason why yo are not using the tracking tools provided in Motion?



  • Adam Scoffield Level 4 Level 4 (2,835 points)
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    Apr 24, 2012 4:12 AM (in response to nelso171)

    to fixed the resolution of a layer, select the layer and go to the Inspectors Tab -> Group Tab. There you can click on Fixed Resolution. and chnage the size.


    I think its bizarre the way you can select you own answers as correct. Do you get the points as well?



  • Adam Scoffield Level 4 Level 4 (2,835 points)
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    Apr 24, 2012 4:46 AM (in response to nelso171)

    hey I'm married with two cats! what are the chances of that? Bet you don't have a Devon Rex though!


    good luck with the move, and with the film, post back here to show it off, or find me at moojoose dot com.





  • fox_m Level 4 Level 4 (3,335 points)
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    Apr 30, 2012 2:07 AM (in response to nelso171)

    You don't need a mask if you're doing rectangular shapes.


    Clone your original source (type- K).


    Crop your source to the rectangle you need around your subject (click and drag on the numbers to go past the slider imposed limits). Use the rectangle shape you'll be using in the animation as your guide for dimensions. [If you're using a shape rectangle, turn off the fill, use an outline width that will be easy to match points with and place it over the clone layer.]


    Type A to turn on "Animation" (recording). [it's easier to start at the first frame of the animation, but it really doesn't matter: you can go back and forth in time and even overwrite settings for any frame if you need to tweak anything.]


    Select the clone layer;  right click on the clone and select Distort from the popup (or select it from the Tool menu). You'll be animating Four Corner. With the Animation recording on, you can use whatever else is at your disposal as well (position, rotation, scale and shear.) If there's not a lot of change in the frame orientation, you can click and drag inside the Distort (Four Corner) to reposition all four corners at once.


    Go frame by frame to set the corner points. Or, if there is actaully a frame in your video, you might try setting up motion trackers [Behaviors menu > Motion Tracking > Analyze Motion. Then for each of the Four Corner parameters, right click and select a Track parameter behavior. In the Behaviors tab, for the Track parameter behavior, drag the Analyze Motion Behavior for the matching point onto the source well.]



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