Looking for advice on tough sky replacement (getting rid of powerlines)

Attached is a picture showcasing what I’ve done so far. I’ve been using the Master Keyer, but I’m having a lot of trouble getting rid of the powerlines since they’re the same color as the trees.

I was wondering if anyone had any suggestions for how I should proceed. I tried to make a big mask to cleanup the matte more, but the edges (where the powerlines connect with the trees) are still problematic for me. I also tried painting each frame, but I wasn’t able to keep it consistent/I still lost details.

Any advice is appreciated!


I’m assuming it is not a locked off shot. I would use the “tracer” function in gmask tracer, then expand the trees a bit with pixel spread in the final comp.

You’re going to have to make your own sky patch, and use a new tree line from the tree in the left to either front source or track in a new “tree top.”

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No one thing is going to do the trick. Tackle the big easy chunks first and then narrow your focus to the smaller bits.

That’s pretty basic advice, so here’s some specifics that may help:

1-point stabilize each region that’s hard to paint, then paint the stabilized bit and unstabilize it.

You could also try whacking a giant median filter on there (found in the Denoise node) and see how much of the powerline that chews up. (see also edge erode if you’re working on the matte)

Lewis Saunders’ new Shader_Dilate might be a help getting rid of wires before the matte is pulled. Shader: Ls_Dilate, but i as andy_dill says, there is probably no one magic bullet. It will be a combination of things.

You could give ls witeless a go - it can do wonders.
Also if you make an open spline gmask line with the power lines, then take that matte and run pixel spread contract. Could help.


i’m assuming that’s a camera move but if it’s not or there is no parallax you could just paint up 1 nice looking frame (essentially a matte painting) add some film grain and track it in there. that way you are only keying the car and roadway which looks like way less work…


Sometime multiplying the original sky (with relevant adjustments) over the new sky helps bringing back detail. You may need to articulate mattes for it.


Oh, if you are able to post a QuickTime, awesome. If youd rather not in public, I get it. You are always welcome to join the Discord and you can screen share privately if youd like a second opinion.


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You’ve had some really good tips and suggestions already. The only thing I would add is some general advice.

“The bigger the lie, the more people will believe”

If you take out a large part and restore bits like the tree, car and barrier it might look like there has been less work than if you try and take out thin wires and metal poles. I have heard it called the predator effect. Where the camouflage looks good until it moves. Big soft patches are much less noticeable.


Here is what my sky replacement with the powerlines looks like (in video form), and another video of what I’ve tried so far. I’m still not sure how to use some nodes (such as Gmask Tracer, I had trouble finding an updated tutorial of it online), but everyone’s suggestions are helpful!

In my recent attempt to get rid of the powerlines I used an erode node along with matte edge, but it took out a bit more detail than I’d like.

Sky Replacement with Power Lines (video)

Sky Replacement w/o Power Lines- attempt (video)

The problem is focused at the last tree. What I would try is comp a full sky plate in that part and freeze and track that tree. With motion blur I think it is quite doable.


Make a new tree, bigger (just a little bit) and track it in.


I know the powerlines are undesirable, but they did balance the shot a bit more. Now there is this gigantic sky blob. Maybe add more trees or clouds? May not be your decision, but worth considering. That may also solve other problems like the chopped up sign and last tree boundary.

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I would also work on the color of the sky, it breaks apart in my eyes before I even see the edge/matte issues where the powerline was.


Something I tend to do to handle those edges is the following:

  • Create an MB map with Motion analysis using the original, one direction is more than enough depending if you are working with or without handles, and render it apart to improve the interactivity.
  • I guess you already have the matte.
  • Use the Motion Blur node with the image already comped and use the MB map
  • Create an edge of your matte (check width) and apply MB just on the edges
  • Adjust MB

This works like a charm. It is not bulletproof but… a lifesaver.

I hope this can help.

I use this alot, maybe will be helpful for you