Masking in After Effects

[jkerry211]

I have a video which I would like to mask the subject giving a lesson.  He moves back and forth and evens raises his arms at time.

I am looking to try and alpha out the background and keep the speaker shown, but each time I try he moves out of the mask and when I look his arm are not in the mask.

Is their a way to keep the subject completely within the mask by using the track mode.

I have tried it in both AEF CC5.5 and CC2014.

Thanks,

Jeff K.

[Roei Tzoref]

this is called Rotoscoping and there are various techniques to achieve a good "roto". choosing a proper technique is based on the type of footage. if you upload a part of the footage via any legit cloud service, we could give you some pointers. sometimes we do the whole thing!

in the meantime here are some resources:

Managing and animating shape paths and masks in After Effects

Use the Roto Brush in After Effects

Roto Brush and Refine Matte in After Effects

After Effects CC tutorial: Rotoscoping with paths | lynda.com - YouTube

[jkerry211]

I don't have a cloud account but can email you a zipped clip.  My email is [email address removed by moderator - please don't post personal information in a public forum]

[Roei Tzoref]

gmail has free cloud, also dropbox. I would prefer to keep this communication public so that others can get a shot at it too and learn something or offer an alternative.

[jkerry211]

Never set up Dropbox but here is the link it gave me for the video.

Dropbox - test-1.mp4

Jeff

[Roei Tzoref · Accepted solution]

o.k let's talk about workflow.

1. how long do I have to Roto?

first thing you should do is determine how much of this footage you need to be rotoscoped. set the in and out point of the frames you want to roto. rotoscoping is a laborious process and you want to work as efficiently and as little as possible. this is a preparation step you can take in your editing software or in Ae. trim your footage to only the part you need to handle.

for example here I have trimmed the footage and the duration to only 4 seconds I want to work on

2. how many pixels do I have to Roto?

next step is determining how much pixels you actually have to roto. do I really need the whole person including the desk to appear on a different background? or do I just want to place another image on the background which means I only need to cut a smaller part of the person. here for example I set guides to show me what I need to roto. I have scribbled here in green - the part I want to roto, in red - the new background

3. Choose a Technique:

to handle a cut-out of an image from a noisy background you can:

1. use masks with keyframes: https://helpx.adobe.com/after-effects/using/animating-shape-paths-masks.html

read carefully the rotoscoping tips in the help files. there is more to it

2. use Mocha that allows you to track and roto the person in one step: mocha AE Creative Cloud Rotoscoping Demo with Mary Poplin at SIGGRAPH 2013 - YouTube

3. use Rotobrush: the workflow is described in the links I sent earlier

here's a interesting article: https://www.fxguide.com/featured/the-art-of-roto-2011/

as you can see - this takes a lot of work.

Good luck

[jkerry211]

Roei,

It does look like a great deal of work.  They were looking to do the whole video which is an hour and twenty minutes long.  Will have to go back and let them know that we would have to do pieces of it to make it work and just past the section intro the video and not try the complete video.

Thanks for all the help.

Jeff

[Roei Tzoref]

It is a lot of work. of course if you shoot the video you can use a greenscreen and avoid  90% of the work but this is not always the case. Let us know how it goes  

[Rick Gerard]

On average if I'm asked to roto footage that was not shot with rotoscoping in mind, which is exactly what you are dealing with here, i estimate that 30 seconds of video will take a minimum of one hour to roto if I'm lucky and can use tracking and other tools to pull it off. One hour and 20 minutes is 80 minutes so that's 160 hours of work. I'd be surprised if you could pull off the roto of your sample video in less time. Average hourly rate is probably somewhere between $95 and $120 per hour if you are dealing with someone that is actually trying to make a living at this so the bid for your project would be somewhere around $16,000 us so maybe with a discount you're talking $10,000. You could bring the guy in and shoot him on Greenscreen for far less than that.

[Roei Tzoref]

and there is always the option to outsource this job to some rotoscoping agency that does this type of work professional all day every day. maybe they can do it for you for far less money... though I can imagine such a place can easily be a modern sweatshop of our times with under-paid animators in some 3rd world country so probably a good idea to see that's not the case first.