Rope/Wire Removal workflow for moving shots

[Matthew Sorrels]

Using mocha Pro’s remove module you can remove the rope but you’ll have to paint a half-dozen or so clean plates to handle the fact you really can’t see behind the rope in the shot(you can’t use the auto-remove feature you really must use clean plates). They recently did a really great webinar on the remove module. It covers everything you’d need to do and then some:

https://www.imagineersystems.com/videos/webinar-replay-object-removal-with-mocha-pro

Another way you might be able to go is track the rope (I’d use mocha but you might be able to do it with AE’s new tracker feature) with a loose shape. Then use a luma key to extract just the rope (since it’s pretty much black). That will get you a very tight matte on the rope, which you can then apply to a copy of the footage offset in the X direction by 40-50 pixels. I’m pretty sure I’ve seen a Video Copilot tutorial that uses this method but I couldn’t find it. It’s not really that complicated you are kind of using the matte as a offset clone stamp. You’ll have to do a bunch of work to get edges to feather and blend to make this look decent.

In both cases you are also most likely going to need to go in and do a paint pass, using AE’s paint effect (be sure to set the duration to single frame when doing simple touch ups). A few clone stamps and some simple brush work to fix up anything that stands out.

[Andy Williams]

Hi Matthew,

thanks for the reply and your suggestions

I started working on the offset method you suggested and I think with a bit more work I can get rid of that rope. I would have loved to have used mocha to do the removal however I think I can’t use the clean plates due to the moving grass in the wind behind the rope? I’m getting some strange effect when mocha starts removing the rope with the clean plates, its like its just replacing them with a static texture and it looks really poor, but its probably just my lack of experience with the software.

[Matthew Sorrels]

You are likely to have problems with the moving grass what ever way you make the patch. Blur and feathering can go a long way on textures like the grass though. Either way you may have to create a second patch from the nearby visible grass and use it to replace a larger area behind the rope. Trying to fix just the grass behind the rope is a lot harder than replacing a larger piece of background with a clone.

Using clean plates with mocha’s remove module is tricky, it rarely works the way you expect. The tutorial I linked to is really very good though, well worth the time. In this shot it’s very possible you just can’t get a mocha generated patch that is useable. The offset cloning will work but getting it to blend right might be harder than you’d like. Shots like this generally might take a few tries to find a method that works and don’t be afraid to paint to fix things.

[Ross Shain]

Some good advice from Matthew.

The trickiest removes are when the back ground is changing in every frame such as leaves blowing in the wind. In these scenarios it is very difficult to have an automatic solution and is usually accomplished by combining a couple techniques: clone, paint, patch, etc.

If the clean frames do not exist within the shot, you need to create some clean plates.

Sometimes it is simply a time saver to use Remove Module to get you 80% there, than fix the remove with patches. It all depends on the shot. Other times, you might want to consider using the mocha data to stabilize the focused area, do your paint/clone fixes, add motion back in. mochaImport+ script for AE is quite useful for this.

Best,
Ross

Ross Shain
Imagineer Systems
http://www.imagineersystems.com