• Adobe After Effects

  How to place black sensor bars over a shirt?

  Posted by Edward Calabig on January 21, 2008 at 10:14 am

  I need to place black sensor bars over a shirt in scene with multiple cuts. What’s the best way to do this?

  I’ve tried making a subtraction mask in the shape of rectangle, but I can’t get AE to motion track it properly… what am I doing wrong?

  Also, is there a way to keyframe it by hand? The rectangle constantly changes shape and I think this might be easier. thanks.

  Steve Roberts replied 18 years, 4 months ago 2 Members · 3 Replies
• 3 Replies

• 

  Steve Roberts

  January 21, 2008 at 1:40 pm

  Make a black solid, then draw a rectangular mask on the solid.

  option 1: Keyframe the mask shape property, then scale and move the mask when you have to.
  option 2: keyframe the solid’s scale and position properties when you have to.
  option 3: keyframe the solid’s scale when you have to, but for position, track the shirt and apply the tracker to the solid’s position.
  option 4: apply the tracker to the solid’s position and rotation, then keyframe the mask’s shape when you have to.

  I’d do #4.
• 

  Edward Calabig

  January 21, 2008 at 7:34 pm

  Ok to do #4 do I just make the mask, then right click the source clip and hit track motion?

  If so, how do I apply it to the mask layer? Whenever I go to target and try to select the clip, it’s grayed out and I can’t target the mask layer.

  Is there a tutorial on here that shows how to do this? Thanks!
• 

  Steve Roberts

  January 21, 2008 at 8:05 pm

  Here’s what I just did:

  – import footage, add to comp
  – make black solid, mask it
  – select footage layer, open tracker controls
  – select motion source (footage)
  – hit “track motion”
  – target is automatically selected as black solid, but you might have to edit target
  – “analyze” the track
  – hit “apply”

  There should be more in the Help.

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