Adding Graffiti in background

[maxd41579327]

Hi everyone i run in to a problem im using the motion tracking tool to add an image in to the background. i need to add a graffiti pice on the wall. Then the camera pans away. it works well until the pan then the image jump all over the place how do i give it a fixed location.

[Roei Tzoref]

you are probably using point tracking. there are number of ways dealing with a tracking that goes off screen: if it's a wall then tracking through Mocha seems like the obvious choice. it tracks planes and not points so it can use a lot more information. also the 3d camera tracker could be good in those situations because it tracks the camera and not the object. so if an object goes off screen, you can get a useful tracking data in certain situations and there are ways to make point tracking work out too.

we need more information about your shot: upload the footage if you can, and specify which method of tracking have you used and how.

[maxd41579327]

color corrected.mp4 - Google Drive

It should be on the wall between the threes once the camera pans it starts to Jump around.

[Rick Gerard]

I would use Corner Pin tracking from Mocha to do this shot. The first step is to trim the shot to include just the frames that are going to contain the graffiti. Use this technique and you should be fine:

The TV in this tutorial is the part of the wall that contains the graffiti.

You'll need to put a hold out spline on the guy in the scene. There are also a lot of rolling shutter errors in your footage. You should probably fix that before you do anything else.

if I get a chance later today I may show you how to do it with your footage.

[maxd41579327]

thank you ill give this a shot

[Rick Gerard]

You might want to also look at this thread: Rotobrush Shortcuts?

I used some screenshots from your project to explain the most efficient way to set up a rotobrush project.

[maxd41579327]

Thank you thats was really helpfull

[Roei Tzoref]

I agree with Rick. from examining your shot this would probably best tracked in mocha which is great for plane tracking. it appears you have color corrected your footage (the name of the video was a giveaway too) and you really should not do that before tracking unless it is for contrast purposes and that could be the case sometimes. the vignetting could make this track more difficult and you are throwing away information that could be useful.

as for the rolling shutter Rick addressed in your shot - as you can see the warping during the pan creates what's supposed to be a straight pillars appear slanting. this affects the appearance and also the tracking. in Ae you have rolling shutter repair effect and this can help you with this.

as for tracking here are resources for learning how to do this in Mocha: Tracking and stabilization motion workflows in After Effects

this track would involve a track matte in mocha for the guy that obscures the plane. and probably some manual here and there to help mocha. after you pasted the data in Ae, you will have to deal with rotosoping the guy but good news there is good contrast. it all depends on where exactly is the graffiti but maybe extract effect and refine soft matte could work it out. if not that then rotobrush may produce good results.