Greenscreen Motion Tracking Tape at DVinfo.net

Darren Odonnell · March 28th, 2008, 07:40 PM

Hello, this is my first post.

I am working on some stuff that was shot on a greenscreen. I have motion tracked the footage but am having a problem getting rid of the tracking points on the walls (what looks to be masking tape, very white).

I am working in After Effects and have used keylight to get rid of the green then did an autotrace for the masking. When I do the autotrace it puts a mask around the performer and a mask around every white X on the walls.

I've tried to delete the masks that I don't need (all except the performer) but it looks like autotrace changes the numbering of masks as it goes through time. I am guessing when the performer moves in front of an X then the number of masks on screen changes and the resulting numbering sequence gets all gimpy.

So i guess I am looking for some guidance on how to get rid of the white tracking markers that were on the greenscreen wall. Or more specifically where in the After Effects workflow I have gone wrong.

Thanks

Darren

Andrew J Morin · April 1st, 2008, 11:09 AM

Increase the number of pixels that the auto-trace uses as it minimum area. I forget that actual name of the field in the dialog box for that, but my guess is that you left it set at 0. Increase that to maybe 10 to 50 pixels, and "test" it.

Peter Manojlovic · April 1st, 2008, 01:08 PM

Do you have real estate to create a garbage matte?? That might help a bit..

Andrew J Morin · April 3rd, 2008, 08:47 AM

Another thought: if you've keyed the footage, the tracking marks should already be gone. Perhaps you need to increase the 'strength' of the key, to pull the trackers out. Or you may do well to use //two// keylight effects, the first to pull out the trackers only, set the result display ("final result" is the default, "status" will show the Alpha mask...) to "Intermediate Result," (which shuts off keylight's color correction routines) then use a second keylight effect to pull the screen out, and set that to "final result." Then you'll be able to trace the foreground only.

March 28th, 2008, 07:40 PM	#1
Darren Odonnell Tourist Join Date: Feb 2008 Location: Fredericton, Canada Posts: 2	Greenscreen Motion Tracking Tape Hello, this is my first post. I am working on some stuff that was shot on a greenscreen. I have motion tracked the footage but am having a problem getting rid of the tracking points on the walls (what looks to be masking tape, very white). I am working in After Effects and have used keylight to get rid of the green then did an autotrace for the masking. When I do the autotrace it puts a mask around the performer and a mask around every white X on the walls. I've tried to delete the masks that I don't need (all except the performer) but it looks like autotrace changes the numbering of masks as it goes through time. I am guessing when the performer moves in front of an X then the number of masks on screen changes and the resulting numbering sequence gets all gimpy. So i guess I am looking for some guidance on how to get rid of the white tracking markers that were on the greenscreen wall. Or more specifically where in the After Effects workflow I have gone wrong. Thanks Darren Attached Thumbnails

April 1st, 2008, 11:09 AM	#2
Andrew J Morin Regular Crew Join Date: Dec 2005 Location: Chicago, IL Posts: 140	Increase the number of pixels that the auto-trace uses as it minimum area. I forget that actual name of the field in the dialog box for that, but my guess is that you left it set at 0. Increase that to maybe 10 to 50 pixels, and "test" it.

April 1st, 2008, 01:08 PM	#3
Peter Manojlovic Major Player Join Date: Jun 2007 Location: Hamilton Ontario Posts: 769	Do you have real estate to create a garbage matte?? That might help a bit..

April 3rd, 2008, 08:47 AM	#4
Andrew J Morin Regular Crew Join Date: Dec 2005 Location: Chicago, IL Posts: 140	Another thought: if you've keyed the footage, the tracking marks should already be gone. Perhaps you need to increase the 'strength' of the key, to pull the trackers out. Or you may do well to use //two// keylight effects, the first to pull out the trackers only, set the result display ("final result" is the default, "status" will show the Alpha mask...) to "Intermediate Result," (which shuts off keylight's color correction routines) then use a second keylight effect to pull the screen out, and set that to "final result." Then you'll be able to trace the foreground only.