Any help with MatchMove please: BCC Continuum on Avid

I have previously asked on the forum but no response. I’m working on a show together with another vfx editor at present but he is forcing me to use Avid’s animatte, spectramatte, ecetera because he says we can’t figure out how to track backgrounds into a shot. Needless to say this triples the time to do roto work or pull a nice key.
I can’t figure out from the documentation how to make this effect work.
V1 - the background/clean plate to be used
V2-V6 potentially - elements or matted out talent, here I have applied the Primatte Studio or Pixelchooser effects

So very basically, to which video track am I applying the Matchmove effect? I want the background to match the movement of the V2 clip. So I need to get the tracking info from V2 I imagine. I would assume I can use the tracking I did when creating the masks but where do I export the tracking information, there is no button to do this.

Where it gets very confusing to me is the MM Foreground and MM background input. If I am putting the Matchmove on V1 then surely I do not have any layers below. How do I point it to the V2 track?

Or do I have this completely wrong?

Hi,

Ok, let’s see if we can help you with this. Here are the steps that I would recommend using to matchmove a foreground graphic into a background shot.

(1) stack the timeline with a foreground graphic with a title matte effect on v2 and the background clip on v1.
(2) apply the bcc matchmove filter directly to the graphic on v2 - do not hold any modifier keys when adding the filter to the graphic
(3) in the effect editor, go to the title matte group and enable the apply to title matte option
(4) in the effect editor, go to the match move group in the filter controls and set the render to move over background, set the foreground to filter layer, set the background to 1st below
(5) in the effect editor, in the motion tracker group, click on launch mocha motion tracker - this will bring up the mocha custom GUI
(6) use mocha to track the background movement and close mocha once tracking is complete (I would recommend placing the blue crosshair that is labelled Absolute onto the area where you’re tracking so that the move will be centered in this area
(7) the foreground graphic should now follow the tracked motion from the background source shot.
(8) if needed, you can adjust the tracker motion by increasing the values in the smooth motion data parameter - I would recommend enabling the show motion path option so that you can see the amount of smoothing that you’re applying to the tracked data. Don’t forget to disable the show motion data once finished or it’ll be rendered into the final result.

I hope this helps!

Cheers,
Peter.

Hello Peter

Thank you for the detail steps, if you don’t mind I will write below.
I need to use Primatte studio on the V2 clips to drop out the blue screens and then need to track the markers so I can attach the background plate.

Corné Gildenhuys

PeterMcAuley Senior Product Manager
May 23

Hi,

Ok, let’s see if we can help you with this. Here are the steps that I would recommend using to matchmove a foreground graphic into a background shot.

(1) stack the timeline with a foreground graphic with a title matte effect on v2 and the background clip on v1.

I am using Primatte Studio to remove the blue screens so I drop that on V2

(2) apply the bcc matchmove filter directly to the graphic on v2 - do not hold any modifier keys when adding the filter to the graphic

I have to hold the modifier key though if I have the Primatte Studio effect, isn’t that correct? Or do I step in and drop it on the clean shot? I assume that so I did it as such.

(3) in the effect editor, go to the title matte group and enable the apply to title matte option

I do that, but now the clip looks strange, kind of transparent. Like an X ray.

(4) in the effect editor, go to the match move group in the filter controls and set the render to move over background, set the foreground to filter layer, set the background to 1st below

(5) in the effect editor, in the motion tracker group, click on launch mocha motion tracker - this will bring up the mocha custom GUI

I launch the Mocha tracker window but there is no image to see - the little tracker is there but the clip is not visible.
This is as far as I get.

Hi Corné,

I think the problem is that you’re applying the MatchMove to a filtered clip and this might be the cause of the issues that you’re seeing. I’ll find and offer a solution for you with a live key as the foreground clip.

I’ve been thinking about this between other tasks and the best solution I can come up with at the moment is to export the keyed clip as RGBA, then import it and if you do that then you should be able to follow along with the steps per my description above. This will at least provide you with the means to finish the work and in the meantime, I’ll think more and consult with some folks to see if there is an alternate solution.

Cheers,
Peter.

Thank you Peter.
A workaround is to do tracking with the Avid tools first working on V1. Then apply Primatte Studio or Pixelchooser to V2. I tried that and it works.

That’s a great workaround actually. Thanks for sharing that.

And in the meantime, we’ll work to correct the compositing issue in the BCC Match Move filter so that you can actually use the filter as intended.

Thanks,
Peter.

Thank you, that would be great.

Hi,

I investigated further and I believe it should work fine for you with Primatte Studio applied and Match Move Alt Dragged onto it, but there is one step that’s easy to miss. Set the Background Layer menu in Primatte Studio to None. This will keep the alpha channel of the key “live” so Primatte Studio doesn’t composite immediately over the background. Then the Match Move filter will correctly pick up the live alpha from the key and it should give you what you’d like.

  • Put the background on V1 and the greenscreen clip on V2
  • Apply Primatte Studio on V2 and key as usual
  • MAKE SURE BACKGROUND LAYER IN PRIMATTE STUDIO IS SET TO NONE. (Will temporarily appear to composite over black.)
    -Alt Drag Match Move on top of Primatte Studio
    -In the Match Move group set the render to move over background, set the foreground to filter layer, set the background to 1st below
    -In the effect editor, in the motion tracker group, click on launch mocha motion tracker which will let you track the background.

Cheers,
Jason

Hi Jason

Great, I will try this out for sure!
Thanks for the clear instructions.

Corné Gildenhuys

Thank you so much, so far it is really working well for me.

Glad to hear it! The key to passing a “live” alpha channel from one effect to another stacked effect in Avid is to make sure the upstream effect has background always set to None so it doesn’t flatten the composite too early. That way way it can hand off the alpha to the next effect where the real composite will happen. You could stack as many filters as you’d like and keep passing a live alpha from one to the next if desired as long as the composite is saved for the last filter in the stack. Note that Sapphire and BCC+ filters usually default to Background of None, but the regular BCC filters default to First Below generally so they require changing to None to preserve alpha. (Note this workflow is specific to Boris FX filters in Avid.)