Screen Replacement: Planar Surface Issue

Hey I’m tracking a phone screen in Mocha and I’ve tracked the phone successfully. However whenever I position my PLANAR SURFACE and track forward the surface does not move. I’m not sure if it has to do with the movement in the clip. I’ve attached a link to the video and stills below showing the issue.

Can anybody offer any advice on how to correct this?

Thanks in Advanced


pw: 12345

Are you wanting to Track the actual Phone screen? This is not what you did, NOOB here . . this what I did:

1] Layer 1 tracked the EXTERNAL edge of the Phone. Several times I had to change the Motion Params.

2] Added a Layer 2 which was the best shape for the INNER screen edge and then Linked to Track 1.

Maybe there is a better method to get your question answered, but I get a good tracking of that inner screen.

Very often you won’t track exactly what you want to replace, since there might not be enough texture to track.

Thank’s I’ll try this.

Do I need to worry about the Planar Surface?

Hi there,

OK, first, go into your clip tab and drag the yellow dashed line to block out both of those black bars, your track will get stuck on them and you need to tell Mocha to ignore them. That’s probably what your track got caught on, as evidenced by your stationary surface tool.

You absolutely need to worry about the planar surface tool, as that is the track. The spline is just where the track is looking.

You want to avoid any reflections on the screen, you can do this with overlapping shapes on the same layer by using Add to X-Spline OR you can simply draw around the edge of the phone. Just avoid the middle section with the reflections.

Because this screen is so small, you may need to use adjust track to correct the surface tool to match perfectly. The surface tool is what your corner pin will be when you are done.

I highly recommend watching our getting started with Mocha series to get familiar with how Mocha works, it’s free to watch online or your can purchase them to watch offline. Boris FX | Videos


Hey Mary,

Thanks for your advice.

A quick update and follow up question.

  1. Changing the clipped dashed line helped a lot as did avoiding reflections on the phone screen.

Follow up question.

How do I reposition the surface tool and maintain it’s previous position at the same time. It doesn’t seem to work like the S-spline where a key frame is generated when you adjust it’s position at another point on the timeline.

The two screengrabs below are as far as I’ve been able to get. Is there something I’m missing in terms of getting the surface tool to stay with the X-spline?

Thanks in advance for your help.

Hi Temi,

You can’t change the surface tool with the spline, the spline is just where the track is looking and the surface tool shows what the track is doing. Also, the “yellow dots” cropping tool won’t avoid the reflection, just the black border. I just want to be clear so you know what the tool is doing.

You CAN however correct your surface tool with the adjust track tool: Boris FX | Quick Tip: Adjust Track

Try that and see if it helps! And let me know if you have any more questions.

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Hey Mary this helped a ton. In regards to the adjust track. When adjusting the the red reference points what is the best way/area to target? In the clip I’m editing I was looking for the corners of the screen. However the top and tail of the shot the phone is positioned where I’m unable to locate the corners. Is there a way to track the corners with the adjust tool in those instances?

I would look for any features I can find that I can see throughout the shot that are on the same plane. Corners of logos, any lights on the device, that sort of thing.

Otherwise, you look at the edges of the surface tool and see if they are where they should be and use your best guess for the points you can’t see by looking at edges.


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Hey Mary. I finally have my surface tracked. However when I copy the tracking data and go back to AE the tracking seems off and very shaky. I thought the best way to bring in tracking data is just to copy to clipboard then paste to the image you want to insert. Am I missing a step because after all that tracking the movement doesn’t line up at all. Any help would be great.

*I’m still working through the training videos so forgive me if I stumble upon this answer later.

You might be either pasting in on the wrong frame (not the first frame) OR you might not have the insert be the same size as the comp, which can also cause this issue. Boris FX | Align Surface and Mismatched Resolutions