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  • Lower Half Drop Out

    Posted by Brian Lynn on April 10, 2008 at 12:53 am

    I recieved a file from a friend who shoots with a HVX200. He brings his footage into FCP and encodes Animation, Best, Millions+…

    Its a green screen shot so he handed it off to me.

    So I’ve dropped the shot in AE, looks great. Apply some basic masks to remove large chunks of the scene (to get rid of grip gear, etc.) and apply Keylight. Key looks decent for a rough job… (I go back later and utilize Aaron’s Super Tight Junk Matte tutorial method to clean it up more, but I wanted a quick look to show client)

    So now I’ve got my subject with the green keyed out, and all is great.

    Next I applied a Linear Wipe transition effect to the keyed layer, and set it to wipe on from the bottom up.

    I set my work area to a 10 second section close to the head of the project, and hit 0 for a ram preview…

    Here is where it looses it… The top half of the image is just fine… but the bottom half glitches. I mean literally the screen is cut right in half, 50/50. Top half is stable, the bottom half drops out in random frames. And only for a single frame.

    If I sit on a glitched frame and change anything at all the lower half comes back… But another ram preview and the glitch is back.

    I finally scrapped the whole project and started over, once the client left, and re-did all my junk mattes, and re-did the key and all looks great so far.

    I’m kinda nervous to introduce the Linear Wipe again because I think its what caused the glitchy drop outs… The idea is to turn the subject into a hologram, similar to (I think its Aaron’s again…) the tutorial, but with a few more tricks and tweaks, including appearing to “turn on” and project up from a base… hence why I was using the wipe from bottom up… Eventually I would have pre-comped the subject and used the wipe on that, but fast demonstration of what a final might look like was needed right then.

    Any ideas on what might have caused this? It was very frustrating and embarrasing to have my client there and watch my AE acting up after I had just finished promoting how much I love AE!! lol

    Thanks for any ideas you might have =)

    Brian

    Brian Lynn replied 18 years, 1 month ago 2 Members · 2 Replies
  • 2 Replies
  • Ben Griggs

    April 10, 2008 at 1:06 am

    Brian,

    It sounds like you just really messed up with the keyframes, like flipping around the time line while adjusting the transition completion. Go back into that AE file and look at the keyframes on that layer. It seems there should only be 2 unless your looking for more static in the movement.

    Another thing is, if it seems totally random, look at the expressions for that layer. It may have been linked to some other property with the pickwhip pinwheel thing.

    In general the wipes provided with AE have always operated very smoothly for me unless I have overlooked something like that.

    Hope that helps,
    Ben

  • Brian Lynn

    April 10, 2008 at 5:22 am

    Hey Ben thanks for jumping on!

    I actually had not yet added any expressions, all I had was the key and the wipe. Client wasn’t really interested in how I made the hologram, they were more worried about the key.

    So at the time I had the glitches (which was cutting the comp perfectly in half on the horizontal, single frame, drop out and come back next frame) I had a very basic comp with a fairly clean quickly roughed in key, and then added the wipe. Did my ram preview so the client could see the key and sign off on the wipe effect, and that’s when I got the glitches.

    Its fixed now, I trashed the comp I was in with the client, started completely over (not a big loss) and now I can’t duplicate the drop outs. So I’m not too worried about it, was mostly just curious if anyone’s seen this before, or if there was something obvious in my work flow that caused such an issue.

    Thanks!! =)

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