CS5 Basic Mask Keyframing Question

A

atlfokus

Active member
[FONT=arial, verdana, tahoma, sans-serif]I'm currently editing a music video and am trying to mask out a background window. I've worked with AE before but am far from an expert.

Basically, the camera doesn't move at all during the shot, and the only area I am concerned about is where the artist's shoulder crosses over the area in point. I've tried tracking but had little success. I was hoping you guys could provide me with some tips or pointers to make it as smooth and seamless as possible. Here's what I've been doing so far with sub-par results. Mask the window and put points where the subject's shoulder meets the window frame and his arm meets the couch. I have about 3-5 points in between.

At first I was almost trying to keyframe each frame but that was obviously taking too long so I started doing about every 5th frame.
Screenshot2012-02-13at53221PM.png


Small example of my results:
http://vimeo.com/36731811

My questions to you:
Should I be using "Rove Across Time"?
Should I have more points?
Feather the mask? How much?

Any tips or advice would be greatly appreciated.

Thanks,

-AP[/FONT]
 
I think it might be easier for you if you split this job into two masks. Keep one for the static shape of the window and then draw another one which is the shape of his shoulder. You could try to track it but it's probably easier to just keyframe it, you'll need to go through and manually adjust it throughout the clip anyway if you track because the shape of the mask will need to change.

You also might like to try the automatic roto brush tool but I always use it in conjunction with masks, it can get a little out of control...

It looks like the density of the points on your mask is pretty good. I would feather it a little myself. Depending on the resolution, probably only between 1 and 3px.

Hope something I've said here is helpful to you!
 
Andrew,

Thanks for the info. It makes perfect sense to have 2 masks, not sure why I didn't think of that before. I tried rotobrushing, but the navy on his shirt blends with the BG too much and the roto can't tell the difference.
 
I would recommend you tackle this sort of thing in Mocha, at least in the future. Believe me, if you take the time to learn that particular piece of software, it would make masking (or in this case removing the windows) an entirely different process. The great thing about Mocha (even the version that ships with CS5) is that once you get the hang of it, Mocha will cut down the on the pain staking workload of having to mask frame by frame. Essentially, you would rotoscope key points of your footage and get away with Mocha doing a lot of the work for you.

If approached correctly, you can get away with making about every 5-10 frames in many circumstances and then all you would need to do is export a mocha shape, add it to a white solid (or black) and use luma mattes in create transparency. Unfortunately this info might not be very applicable now but I hope this can help down the road.
-B
 
To be honest, it's not something I personally picked up through tutorials so I wouldn't be able to recommend anything specifically. However, a simple google search of "rotoscoping with mocha" should get you headed in the right direction. Let me know if you find anything useful.

-B
 
You must log in or register to reply here.
Back
Top