FORUMS: list search recent posts

Set Extension -Motion track

COW Forums : Adobe After Effects

<< PREVIOUS   •   FAQ   •   VIEW ALL   •   PRINT   •   NEXT >>
John Jordan
Set Extension -Motion track
on Jun 19, 2010 at 3:39:04 pm

Hello

I have a simple shot where the camera moves up vertically. I have motion tracked the camera movement with three null objects. Near the end of the shot I want to delete a large area of footage and place a picture in the deleted area. This will make a nice set extension shot. Problem is that when I mask out the area it does not stay in place in that particular frame. Is there a method I can follow to solve this problem?

Thanks


Return to posts index

Jesse Toula
Re: Set Extension -Motion track
on Jun 20, 2010 at 1:28:09 am

Have you checked out this tutorial. It talks about exactly what you are doing. (as far as I can tell)

http://library.creativecow.net/articles/kramer_andrew/Set_Extensions.php

-Jesse Toula
http://www.BatchFrame.com


Return to posts index

John Jordan
Re: Set Extension -Motion track
on Jun 20, 2010 at 3:03:45 am

Thanks so much for the response

What I am trying to do is to delete part of my footage. As the camera moves up you see many trees. So what I did was that I selected my video and near the end of the shot my camera moves up to see a woodland of trees.I selected my pen tool and traced the tree area. I went to my masking properties and selected subtract. Now all the trees are deleted and there is a large transparency hole in the footage. I placed a nice picture in the transparency area to make a nice set extension. The problem is that my camera moves. As a result the picture does not stay fixed. So I am trying to learn how to track deleted footage. Because when you select a video and delete a section of the video, the transparency hole does not stay fixed at that position (or that frame).

I tried to look for tutorials about this matter. But so far no luck.



Return to posts index


Jesse Toula
Re: Set Extension -Motion track
on Jun 20, 2010 at 3:47:46 am

Ok, I'm a little bit confused about what your problem is. Are you having trouble tracking the footage? I thought you had tracked it on to three nulls.

Or are you trying to attach the extension to the track?
To fix that you would parent the three nulls to each other so that one of the nulls contains the entire shot's movement. (explained in the tutorial linked in my previous post)

Or are you have a problem with the mask not tracking with the footage?
The problem here would be that the mask is not going to stay with your footage unless it is roto-scoped. What you would want to do is use a matte. Copy your mask to a solid, then parent the tracked null to it. Then use the solid as a matte for your footage, that way the transparency you created stays with your clip as the extension does.

Let me know if any of these is what your problem is and I can go into more detail if you need it.

Jesse Toula
http://www.BatchFrame.com


Return to posts index

John Jordan
Re: Set Extension -Motion track
on Jun 20, 2010 at 4:59:03 pm

The problem is the mask not tracking with the footage. I have already tracked the footage with three null objects and parented the null objects accordingly.I just do not know how to track the mask transparency hole.

I also have another quick question. I have done some shots where I tracked footage with null objections. I already know how to parent the null objects. However when I parent a picture to the null object, the picture stays at a fixed position, which is great. However the picture shakes a little bit. I checked my null object key frames on the screen, and they looked straight and linear. Is there method to stabilize the picture so it would not shake?

Thanks so much for the help!


Return to posts index

Jesse Toula
Re: Set Extension -Motion track
on Jun 20, 2010 at 6:21:23 pm

So the reason the mask is not moving is because it is locked to the video layer, which is not moving. What you need to do is create a solid and put your mask onto it. Then place the masked solid directly above your video layer. Parent the masked solid to your tracking nulls. Then on the video layer, choose Alpha Matte (under TrkMat in the time-line panel), This should do it for you.

If you are seeing shakiness in your image, it is probably because your track is a little shaky. Try redoing your track with better track points until you get something that really locks on.

Visit http://www.BatchFrame.com for AE Templates, Stock Footage, Video Tutorials and more!


Return to posts index


John Jordan
Re: Set Extension -Motion track
on Jun 21, 2010 at 2:53:34 am

I did everything you said and it worked. But now my footage is off the composition. It moves down into the comp as I play the shot forward. I think the only solution is to rotoscope the mask. What do you think?


Return to posts index

Jesse Toula
Re: Set Extension -Motion track
on Jun 21, 2010 at 3:54:50 am

No, you should not have to animate the mask. I don't understand why our footage is outside the comp, it should not have been moved at all. Did you put your mask on a separate layer?

Could you upload a screen shot of your timeline window? I think that would help me see what you are doing. I need to see parenting and track mattes.



Visit http://www.BatchFrame.com for AE Templates, Stock Footage, Video Tutorials and more!


Return to posts index

John Jordan
Re: Set Extension -Motion track
on Jun 21, 2010 at 4:11:19 pm

I took the snapshot but I can't upload the picture. I am clicking the camera icon to upload the pic on to the forum but no pop up window came. Is there an email address I can send it to?

Thanks


Return to posts index


Jesse Toula
Re: Set Extension -Motion track
on Jun 21, 2010 at 5:03:26 pm

Yeah, email it here: Email


Return to posts index

Jesse Toula
Re: Set Extension -Motion track
on Jun 22, 2010 at 4:31:25 am

Ok, looks like you need to switch the track matte from alpha matte to alpha matte inverted. My mistake.

Jesse Toula
http://www.BatchFrame.com

Visit http://www.BatchFrame.com for AE Templates, Stock Footage, Video Tutorials and more!


Return to posts index

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