ROtoscoping a complex grid

[Arin5C77]

Hi,

I've been trying to separate a complex moving grid from a white background. I tried rotoscoping, keylight... Everything! But nothing seems to work. 

Imagine, you're moving a manhole grid in front of a white background. Don't ask me why they haven't used a green background, I don't know; 

I need to use that grid for another project; Keylight doesn't seem to work with white. And I can't turn that white into green..

THank you so much!!

[Towerguy · Accepted solution]

Hi, have you tried using a copy of the footage as a track matte?

[Rick Gerard]

Without a screenshot of the footage, it is going to be impossible to point you to an effective workflow. I have about 40 different workflows that I use all the time to generate mattes. Rotoscope is at the bottom of the list. Rotobrush is just up one from the bottom. An awful lot of the keys I create use more than one copy of the source footage stacked on top of each other and pre-composed to create the track matte. 

Show me the shot and I'll run through my approach to the problem.

[Arin5C77]

Hi Rick,

Here's the shot. The camera glides through the pipe, passes through the grid showing the room on the other side. 

Thanks a lot. 

[Rick Gerard · Accepted solution]

I would copy the layer then add Colorama with Ramp Gray. Then add Curves to darken the black. That would give you this if you added a black background below and did a little fiddling.

Now all you have to do pre-compose the two layers and set the pre-comp to inverted luma matte for the footage. Put your new background below and make some color corrections and you have it.

There are more than 20 different workflows that I use all the time to create procedural mattes. The Colorama/curves/Luma Matte workflow is only one of them. 

 

 

[Arin5C77]

Thank you so much!