Motion Capture and Replacement

BasharOfTheAges · Post by **BasharOfTheAges** » Mon Jan 31, 2005 11:12 am

I was wondering what methods anyone could suggest to track motion of certain objects in a clip of video to replace said objects with other objects (i.e. a seperate video stream or a simple picture)

I'm using Primere pro 1.5 btw but have AfterEffects 5; although i've never as much as touched it.

AbsoluteDestiny · Post by **AbsoluteDestiny** » Mon Jan 31, 2005 12:23 pm

After Effects can track motion but you'd have to use a mask to remove an object and it wouldn't preserve the background (obviously). I suggest reading the manual.

BasharOfTheAges · Post by **BasharOfTheAges** » Mon Jan 31, 2005 2:35 pm

well... the object i want to use is of a high enough res to be able to be shrunk to any size; so i can basically plop it on top of the replaced object, i just wanted to make sure it would follow the object it is covering over.

Zarxrax · Post by **Zarxrax** » Mon Jan 31, 2005 2:47 pm

The motion tracker is only included in the production version of AE, and it can also only do 2d tracking, not 3d, which is something to keep in mind.

BasharOfTheAges · Post by **BasharOfTheAges** » Mon Jan 31, 2005 3:14 pm

Right, the motion is 2d although there is some fake 3d atributes to it (i.e. getting larger) the replacement picture is completely 2d and, in fact, is the icon i have for my avatar right now

BasharOfTheAges · Post by **BasharOfTheAges** » Thu Feb 03, 2005 12:59 am

Okay, i get the basic understanding of how to motion track something and overlay an object on top of it. But there still are a few issues i'm having with the process.

1) I need to replace multiple objects on multiple paths with coppies of a single object, how do i set up another track on the same video base?

2) the track dosn't stay at the center of the moving object because it grows in size as it nears the screen (there's depth as well as movement, so it grows in perspective)

3)The multiple objects all grow and move all over, so would there be an easy way to have the image grow as it moved?

*sorry uf 2 and 3 seem like almost the same problem*