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Activity Forums Adobe After Effects Auto-Trace Glitch

  • Auto-Trace Glitch

    Posted by Max Jackson on September 3, 2011 at 4:35 am

    Hi CC,

    I’m not sure if this is a glitch. It’s most likely a user error based on having to much stuff stacked up. But…I can’t figure out why it’s making a box that’s not there. ??

    Like, there’s nothing in my layering that I can see that would tell it to shrink the auto-trace to a portion of the comp.

    I attached an image wondering if anybody’s seen anything like this before?

    Thanks for reading. 🙂

    Max Jackson replied 14 years, 10 months ago 3 Members · 5 Replies
  • 5 Replies
  • Todd Kopriva

    September 4, 2011 at 9:13 pm

    If you post a copy of your project, I’ll have a look.

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    Todd Kopriva, Adobe Systems Incorporated
    Technical Support for professional video software
    After Effects Help & Support
    Premiere Pro Help & Support
    ———————————————————————————————————

  • Max Jackson

    September 5, 2011 at 6:31 am

    Hi Todd,

    Here’s the project:

    2897_hardprofile.zip

    The video needs reloading and the matte is a little chewy because the key is really noisy. Fortunately it’s monochromatic so detail isn’t as demanding.

    Anyway, I thought a simple auto-trace would save a lot of garbage matting and roto. I’m still in the process of re-building the hand alone because of noise destruction, but this auto-trace glitch has me at a loss. It’d be a done deal if I could figure out what I’m doing to cause it non-response.

    Thanks a bunch for taking a look at it. If there’s anything else I can explain to help, please let me know.

  • Roland R. kahlenberg

    September 5, 2011 at 11:04 am

    Kudos to Todd for taking a look at the AEP but it looks like your AutoTrace layer’s perimeter can be seen and it is less than comp size, and that is likely the cause for the white area to appear.

    I’m also not too positive with the effects you’ve used and how you’ve laid them out within the hierarchy.

    Cheers
    RoRK

    Intensive AE & Mocha Training in Asia.

  • Todd Kopriva

    September 5, 2011 at 4:15 pm

    You didn’t include the footage, so I can’t see the boundaries of the alpha channels in your footage layers, but I can tell that you’ve got blending modes operating on the alpha channels of your layers—including the one that you’ve applied Auto-trace to. Auto-trace is going to constrain itself to parts of the layer with non-zero alpha.

    But this is moot, really. Auto-trace is certainly not the right tool for the job if what you’re attempting to do is create a garbage matte or do rotoscoping-like prep work for keying.

    If you want to trace a rough matte around an object in preparation for keying work, try the Roto Brush tool.

    ———————————————————————————————————
    Todd Kopriva, Adobe Systems Incorporated
    Technical Support for professional video software
    After Effects Help & Support
    Premiere Pro Help & Support
    ———————————————————————————————————

  • Max Jackson

    September 6, 2011 at 2:47 am

    Hi Guys,

    I included footage in the zip. It just needed to be re-linked. Sorry, I should’ve done that before posting. In any case, from the sound of it that seems like a moot point.

    I’m not really sure why it wouldn’t work. I changed the setting from alpha to luminance because the subject is completely black. I thought that would do the trick. But if this is really eating spaghetti with a spoon, I’ll try roto brush instead. I’m new to this so I’m not going to try and drive any point home. I just want to get the project finished. I need to re-visit roto-brush anyway. Now would be an ideal time.

    If the stacking is bizarre it’s probably because I’ve thrown myself into the gauntlet against a really dark/noisy bluescreen job and am trying to push channels as much as I can to get a solid color.

    As for the auto-trace’s perimeter, the preview frame is to size. It jumps to that size after the first frame. That’s what I don’t understand. That is, why the preview would look great then stumble at the gate. Denoiser has been giving me a lot of trouble. Maybe that’s tripping it up somehow upon render?

    Thanks for the help guys and sorry for a sluggish response. I’ve been battling bed bugs all weekend.

    Best,
    -maX

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