ADOBE AFTER EFFECTS: Forum Expressions Tutorials Creative Cloud

How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?

COW Forums : Adobe After Effects

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
Alex CameronHow can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 17, 2013 at 12:10:37 am
Last Edited By Alex Cameron on Nov 18, 2013 at 3:10:24 pm

I feel like what I'm looking for is relatively simple, I'm just having trouble articulating what it is.

For the project I'm working on, I need to be able to go up to the wall, touch it, then have an effect based off my hand's imprint. Here's a very crude example of what I'm going for using rotobrush and Mocha:







However I want to be able to pull that 2D plane where the hand is touching so I can apply the follow effect to the wall:







The effect relies on Classic Color Burn so I need that tracked plate to work with. Is there a way for After Effects to project that tracked plane in 2D?


Return to posts index

Dave LaRondeRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 17, 2013 at 6:34:06 pm

Sorry, but I think you'll have to re-articulate. I don't see how a hand gets into the mix.
Is this hand keyed? Hope not: that's a royal pain.
Does the hand plop down in the midst of four tracking points? How do you do "something" under the hand? How do you get rid of the track points?
What's the deal with big blue thing? Is it a really tight shot of one of the tracking points, or is it something bigger?

I get the feeling you're trying to use AE without any knowledge of the basics. That's a sure recipe for disaster, Because AE doesn't work like anything else. You'll just get frustrated while hosing yourself.

Here's a place to spend some nice, long, quality time:

http://blogs.adobe.com/aftereffects/2010/01/getting-started-with-after-eff....

Learn how to use AE from the Pros and not some high school kid on YouTube.

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA


Return to posts index

Alex CameronRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 17, 2013 at 8:29:31 pm

Nah, I've used AE for quite a while but this is my first project that involves tracking.

The hand gets in the mix because it's going to touch the wall, as the hand gets removed we see that there's an imprint of the hand on the wall.

I'm definitely not thinking about hand keying as that would indeed be a nightmare, that's why I wanted to use green screen. The blue thing is just to highlight the tracked area. I should have made it green as that's what's going to be the rough size of the green screen patch.

What I want, in the end, is to have a patch of green screen on the wall. Track it. Take that portion of the green screen, key it out so it's just the hand and replace it with the hand imprint footage as the hand moves out of frame. It would be infinitely easier to key out and work with if I could actually look at that tracked section in 2D as opposed to having it move all over the place as it does right now.


Return to posts index


Dave LaRondeRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 17, 2013 at 9:33:28 pm

If you've AE for quite a while, then you know that if you remove a portion of video, it's customary to replace it with another. If you key out a section of wall, what are you going to use to replace it? That's question #1.

Do you intend to use a hand-held camera for your clean plate? Exactly how do you intend to shoot this? That's question #2.

And I don't see why Mocha wouldn't be perfectly capable of hancling the tracking. Is there something I'm missing?

Dave LaRonde
Promotion Producer
KGAN (CBS) & KFXA (Fox) Cedar Rapids, IA


Return to posts index

Alex CameronRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 18, 2013 at 3:11:49 pm

Dave, I went back and edited my original post. I shot some quick footage to give a crude demonstration of what I'm looking for.


Return to posts index

Conrad OlsonRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 18, 2013 at 5:58:55 pm

I think I know what you want to do. Are you basically trying to stablize your footage based on the planar track, so that the area of the wall stays rectangular in the same place all the time?

If that's what you are trying to achieve then you need to create a reverse corner pin effect. The last time I tried to do this in After Effects I couldn't find a simple solution, and I had to use expressions. But you should look in the export options of Mocha, to see if there is a stabilize or invert option.

---

conradolson.com


Return to posts index


Conrad OlsonRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 18, 2013 at 6:03:29 pm

I wasn't quite clear, you would need to write the expressions inside a corner pin effect. The basic idea would be to pick the frame you want to use as your reference frame, then subtract the corner pin data, for every other frame, from that initial value, it should produce a reverse corner pin effect. You would need the same expression in each of the 4 points.

So something like this (this isn't correct syntax)

cornerpin.point1.x.(reference frame)-cornerpin.point1.x.(currentframe)

---

conradolson.com


Return to posts index

Alex CameronRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 18, 2013 at 6:04:11 pm

Yes! This is what I'm looking for. Do you know if Nuke be able to pull this off? What would I even begin googling for, "reverse corner pin technique"?


Return to posts index

Conrad OlsonRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 18, 2013 at 6:12:08 pm

I use Nuke a lot more than After Effect and it definitely works in Nuke. But I think Mocha has the inverse option for Nuke.

I know that if you do the planar track in Nuke X, with the native planar tracker, it gives you the option to stabilize when you create the corner pin node.

---

conradolson.com


Return to posts index


Conrad OlsonRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 18, 2013 at 6:16:40 pm

I'm in the middle of stuff right now, but if you can't figure it out let me know and I will try and help you with the expression later.

---

conradolson.com


Return to posts index

Alex CameronRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 19, 2013 at 5:14:07 pm

Hey Conrad, I played around with Nuke last night and it worked like a charm. I inverted the corner pin data then exported the footage as a tiff sequence over to After Effects, applied the effect, then rendered a tiff sequence and imported it back into Nuke.

Does that seem inefficient to you?

Also, I've never played with rotopaint in Nuke, do you think it's possible to remove my hand from the footage to create a clean plate or is it too big for object removal?

Thanks for your help!


Return to posts index

Conrad OlsonRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 19, 2013 at 5:39:57 pm

I can see one big issue with that workflow. By undistorting your whole plate, and then re-distorting it after you add the effect, you add two stages of filtering to your plate, which will cause it to soften.

In general you should always try to avoid transforming your original plate, just match any other elements to it. Sometime this is unavoidable though, in which case you should try to limit the area you are effecting.

If you can render your effect out without the plate in the background, then track it back in in Nuke and add it to over original plate, it would be better. If you can't do that, just try and limit the area that you are working with, and keep as much of the original plate as possible.

The roto paint tools in Nuke are decent enough to create clean still frames. You can then use your existing tracking data to track those clean frames in. We do this sort of stuff all the time.

---

conradolson.com


Return to posts index


Alex CameronRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 20, 2013 at 3:34:50 pm

Great, thank you Conrad. I've seen a few tutorials regarding object removal in Nuke, are there any you think I should check out?


Return to posts index

Conrad OlsonRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 20, 2013 at 6:00:10 pm

The only ones I can think about off the top of my head are the ones from the Foundry themselves. They are more about how the tools work, and less about good technique, but they will give you a few ideas. There are quite a few about the planar tracker.

https://vimeo.com/thefoundry

---

conradolson.com


Return to posts index

Alex CameronRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 25, 2013 at 11:17:13 pm

Hey Conrad,

I've been able to make huge strides based on the the advice you've given me, so thank you very much for your time. I've got the footage doing what I want in Nuke and After Effects, now I think it's time to add a little bit more realism.

Because the footage is hand held that means the light is constantly shifting around. While the effect looks okay as it is now it's missing the changing light over the tracked area which I think would help really sell the effect.

My question is: do I add in a 3D light in After Effects or should I do it in Nuke?

My gut is telling me that Nuke is the better option since I can actually do a camera solve to help recreate the room in 3D.

However, I'm unable to just export the effect without the background. Here's what I mean:



The Classic Color Burn on the top layer only works if that bottom layer is visible. If I turn it off it won't work. Which has be in a bit of a jam when it comes to adding a light into the scene in both Nuke and After Effects...


Return to posts index


Conrad OlsonRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 27, 2013 at 8:17:47 pm

Sorry for the delay replying Alex. Work has been crazy.

I wouldn't bother trying to use 3D lights to relight the effect. It could work but I would usually just used masks and colour correction effects. It's much faster and easier to get the result you want.

If you can use the plate itself to try and get the lighting then that is the best way. Try un-premultiplying your effect, experimenting with different blending modes between your effect and your plate, and then premultiplying your effect again with the original alpha channel. This will allow you to get effect the colours without changing the transparency.

---

conradolson.com


Return to posts index

Alex CameronRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 18, 2013 at 6:42:31 pm

Excellent, I'll try this out with Nuke then. I'm assuming I can just attach a write node to the stabilized footage so I can toss it back to After Effects and achieve the effect?

Thank you Conrad!


Return to posts index

Roland R. KahlenbergRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 19, 2013 at 1:46:30 am

See of my recipe in the following thread helps -
http://forums.creativecow.net/thread/2/1043646

Cheers
RoRK

Intensive mocha & AE Training in Singapore and Other Dangerous Locations

Imagineer Systems (mocha) Certified Instructor
& Adobe After Effects CS6 ACE/ACI


Return to posts index

Ross ShainRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 18, 2013 at 7:46:12 pm

This is a very common mocha usage. You should not have an issue using the bundled mocha AE and After Effects to accomplish this effect.

BTW, mocha can export inverted corner pin or another option is the mochaImport+ script:
http://mamoworld.com/tools/mochaimport

Ross Shain
Imagineer Systems
http://www.imagineersystems.com


Return to posts index

Alex CameronRe: How can I extract and "flatten" footage that's been tracked with Mocha to work with it directly in 2D?
by on Nov 19, 2013 at 1:01:21 am

I figured I was missing something obvious in Mocha. I looked around the program and still can't find where to do it. Is it under the stabilize tab?

Thanks for your input!


Return to posts index

<< PREVIOUS   •   VIEW ALL   •   PRINT   •   NEXT >>
© 2017 CreativeCOW.net All Rights Reserved
[TOP]