Tracking Masks

Howdy all! Quick question- is there a technique in which one could track a mask? I think this was answered once but I can't find the original post- or - it may have been buried in a long post somewhere. It's not turning up in the search either.

I've been going frame by frame to make adjustments so I was just wondering if there's an easier way.


  • Masking frame-by-frame is called rotoscoping, and sadly, that's always been a manual process.  Until/unless someone adds the ability to tie a mask's position to another layer's position, it's always going to be 100% manual.

  • @jsbarrett

    "...Until/unless someone adds the ability to tie a mask's position to another layer's position..."

    Mask on a white plane, the plane parented to a point (so you can use tracking), add a grade layer and use a set-matte effect? Would that work?

  • edited November 2017

    If you're rotoscoping don't do it frame by frame. Divide the object up into sections, so head, arms, body, legs if a person.

    For a head, move 8 frames at a time and let Hitfilm interpolate the path between those changes. Maybe even 16 frames. Then, if required, pick a halfway point and add keyframes there. If really unlucky, half the gap again on any fiddly bits. You'll probably only need 8 or 9 keyframes per 100.

    Annoyingly Hitfilm skips by either 1 frame or 10, which is a useless arbitrary number, as 10 can't be halved more than once, so you'd have to go 10 forward, 2 back.

  • @JMcAllister I thought about that, but that means putting the white plane above the footage layer to get the initial mask shape made.  Once you add the grade above the plane and point Set Matte to it from the footage layer, the matte mashes the masked plane plus the footage, so it's no longer just the mask.  You'd have to move the mask and grade layers below the footage for it to work.  And then if you need to tweak the mask, you've got to move the mask back to the top, then back to the bottom once it's fixed...etc.  In the end it might work, but I don't really feel it would be saving work.  I'd almost rather rotoscope than do all that layer juggling.

  • @StormyKnight - Mocha

    Or basically what @JMcAllister suggested. Do a track, add a white plane and copy/paste the tracking data to the transform controls of the layer (there'a reason for this instead of using a point). Put this on top of what you want to mask and reduce the opacity to around 20% so you can trace your mask. When you're done with the roto, reset the opacity to 100% and make this plane a composite shot moving masks, effects and transform properties to the new composite shot. (this is why you copy/paste instead of using a point). Now you can hide this mask comp and use it as a source layer for Set Matte.


  • @jsbarrett

    I tested it... you don't actually need to move the plane layer above the footage... as long as the plane layer is selected, the mask will be drawn on the plane layer. 

    So you add a white plane below your footage, with a grade layer between the two, then select the white plane and draw your mask around the area of your footage you want to mask. 

    And the advantage of using a grade layer instead of an embedded comp is that everything is in the same comp, so it is easier to make changes. 

    I'm not saying this is better than using mocha (because it's not) but I just wanted to point out that it's possible

  • Also I broke my habit, and I made a quick video to demonstrate... partly because it gave me an excuse to play with the new text tool.

  • @jsbarrett  &  @Palacono - Yeah, I've been rotoscoping for weeks now and it's so tedious. I do skip ahead as many frames as I can and then fine tune but the producers that did the filming ignored my advice to the quickest way to get things done i.e. film with a tripod and add camera shake in post and use a green screen!!! Now they want all this stuff in the background removed. Kind of a pain. No- a HUGE PAIN!!!

    JMcAllister   &   @Aladdin4d - Thanks for the video links! I'm confident these are going to save me some time. And JMcAllister thanks for going out of your way. I appreciate it! I'm going to try both of these techniques first thing in the morning after my eyes have stopped spinning from stuff I've been working on tonight.

  • @JMcAllister Thanks for sharing that example video. I'd never tried working on a mask on a lower layer while viewing a higher one.  Kinda nifty!

  • Before I got HF Pro, I picked up the Cyberlink Director suite during one of their online sales, largely because I had seen a video demonstrating using ColorDirector to creak a tracking mask, then changing everything else to green.

    The result could be exported, then imported into HitFilm and the green keyed out.  Was a bit of extra work.  Mocha in Pro can do it much easier.

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