Motion Tracking and Chroma Key in Motion

Discussion in 'Digital Video' started by JimmyB248, Nov 6, 2006.

  1. JimmyB248 macrumors regular

    Mar 8, 2006
    Ok guys, I'll owe the person who answers this for a long old time! Here's the problem, I have a video of a guy talking to the camera infront of a greenscreen. The greenscreen has blue dots stuck to it for motion tracking.

    In Motion, I have managed to key out the green, and key out the blue. However, I cannot key them both out at the same time, if I apply both to the video, then the layer that is on top becomes transparant and the layer beneath turns black. What I mean is that if the blue key is on top then the blue that I have keyed out becomes transparent but the green I have keyed out turns to black. And vice versa. How can I make it so they're both transparent?

    The second question is to do with motion tracking. I have my still image beneath the green screen video. In motion there's all sorts of options to add motion to it and to follow an object but none of it seems to work. Can somebody please please explain to me how to have the image follow the motion of the video layer?

    This is pretty urgent I need an answer by around 8 tomorrow morning (GMT). It's for the job that I am working at and need to have these clips done by tomorrow evening.

  2. Sdashiki macrumors 68040


    Aug 11, 2005
    Behind the lens
    Not used motion for a long time but here goes with some sort of FCP approach:

    can you "nest" items?

    Step 1

    as in, can you apply a filter (one key) to the video file, and then make the filtered video its own video and not a video with a filter on it? In FCP this is called nesting, and is typically used so you can either clean up the time line or do some fancy filter applying. It creates a single video file for the timeline that if double-clicked (opened) brings the "inside" video files into their own timeline.

    Step 2

    that way you have video with the first color keyed out, and can apply a filter to that video, making it comply with the rules you seem to be breaking.

    other way around, export the video from motion and do step 2.
  3. bigbossbmb macrumors 68000


    Jul 1, 2004
    or key out the green and then mask out the blue dots
  4. JimmyB248 thread starter macrumors regular

    Mar 8, 2006
    But masking would not be specific to the the colour though would it, only the area? And the character moves around a lot so I don't think that would work. I will try the nesting option though. Thanks for the help!

    Also, any ideas on the motion tracking?
  5. P-Worm macrumors 68020


    Jul 16, 2002
    Salt Lake City, UT
    I'm pretty sure that Motion doesn't have motion tracking. I think what you are refering to that isn't working are Motion's behaviors that can have an object follow an already animated object (not follow an object in video).

    If you have access to After Effects or Shake, they have motion trackers, but I assume that since you are asking about Motion, you don't have access to either of those.

    There's a good site that has some tutorials on Motion and glancing through the articles you should get a good idea of how the program thinks.

    I don't know Motion that well myself, so I'm sorry I couldn't be of more help.

  6. JimmyB248 thread starter macrumors regular

    Mar 8, 2006
    Thanks a lot for your help, I'm going to see if I can get hold of After Effects. Will the 30 day trial allow me to do it?

    Is motion tracking included in the standard or the business version do you know?

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