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Kathleen JudgeAE- NEED TO MASK way?
by on Aug 5, 2011 at 1:16:04 am

OK. These two objects should've been shot on a green screen & now I'm woefully paying the price.

I was able to key out the poles that held the two objects (balloon & rock-thing) but then the director wants the blue BG to pan left while the balloon and rockthing are drifting offscreen. They were shot in front of the blue gradient BG (& this BG has lightsource just off center).

The objects were destroyed before the director added this new staging. I was able to have camera guy reshoot BG without objects, in the hope that I could pull the balloon and rock out of the original still BG and have them move over the new separated BG. This is a beast.

Not sure if I'm just tired and not seeing the easiest way to do this or if there isn't an easy way (leery of masking each frame of the rock by hand). You can see in this still that I tried rotobrush and masking the rock. The balloon is easy but the rock has intricate edges and blinking lights within it.

Other option I'm thinking is to mask a single frame of balloon, then track the camera drift from the original shot of the rock & balloon and attch it to the new masked rock & balloon & then somehow layer in the lights that blink on the rock....


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Brian CharlesRe: AE- NEED TO MASK way?
by on Aug 5, 2011 at 2:15:57 am

Is there any way you can create a matte from a duplicate of the rock footage using the shift channels effect (or similar channel effects)? Then use that as an alpha matte for the one you want with blinking lights.

The fact that it illuminates may make it tricky...

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Isaiah BugarinRe: AE- NEED TO MASK way?
by on Aug 5, 2011 at 2:22:06 am

I'm a little confused on what exactly is going on with the picture. I'm assuming the picture below the post is a still image of a video, correct?

If so, it seems like the only option you have is to zoom in on the rock, use the pen tool to mask around the rock, and then motion track (probably using the balloon-thing as the tracking point). As for the lights coming out of the rock, I would use Knoll Light Factory or something similar and then put that where the lights are (maybe add some masking depending on whether or not the lights are behind it.).

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Dave LaRondeRe: AE- NEED TO MASK way?
by on Aug 5, 2011 at 3:00:49 pm

If these two objects don't change their shape, and the edges remain constant, You only need to cut one mask for each object. You can then move those masks in any number of ways as necessary.

Then give the director a dope slap.

Dave LaRonde
Sr. Promotion Producer
KCRG-TV (ABC) Cedar Rapids, IA

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Darby EdelenRe: AE- NEED TO MASK way?
by on Aug 5, 2011 at 8:52:30 pm

I would recommend using a combination of methods. Try to create a satisfactory matte with good edge detail from the rock. I'd recommend starting by using a Shift Channels effect to set the RGB channels all to Blue. This will allow you to use a levels effect on the blue channel to try and create a luma matte.

Your matte will have a lot of holes in it, but that's ok. Pre-comp the matte and create white solid layer in the pre-comp. Then you can use a mask applied to the white solid to knock out the interior of the rock image. If the rock moves at all you can motion track the white solid to it.

Might take a good amount of tweaking to get there, but it should be a pretty robust way to mask out your elements.

Darby Edelen

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