Mask a doorway as door opens.

Greetings all,

I created a video of me opening a door and a dino comes up and roars. However I can't seem to get it right with masks. The mask is permanent and so there is a hole not a door and it shows thru to my under layer of the yard outside before I open the door. What do I do to have the closed door and then when I open it, reveal the outside as the door opens? I have 3 layers, 1 - closed door, 2-dino that was on green screen,  3 - clean plate of outside yard. I want to see the yard when I open the door, then the dino comes up and I hide. Easy? I don't think so. When I open the door, I am partially blocking the opening and I disappear because of the mask. Any help on this would be appreciated. Is there a way to start masking as the door is opened and not have it just sitting there the whole time??




  • Triem23Triem23 Moderator

    Welcome to the wonderful world of roto! 

    I'm going to post a Hitfilm 2 Ultimate tutorial on masking. The UI will be different from HF4, but the techniques are the same, and this is still the best masking tutorial for Hitfilm. 

    You'll see in this tutorial how masks can be animated to move or change shape. Your basic solution will be to keyframe the mask position on the first frame you want to see it, then go back in time one frame, and add a keyframe where you've moved your mask out of frame.

  • edited June 2016

    Here is a tutorial I made for a sketch we created. The premise is rotoscoping a wall to reach through it :) Its in FCP but the concept is the same for HF

  • Thanks for the replies. I don't think I can use these though to get what I want. Triem23, I have watched that video a few times since I started with HF 2Ex. I did it again at your suggestion but I think it gave me the idea I need. I am going to put up a green screen in the door way and see if when the door is opened I can see through to the next layer after using the color diff key. It will take me a while to get time to work on it. TfF, I did not understand the relationship of the video to what I am trying to do (a little slow here). So I will watch again later.

  • edited June 2016

    TfF -

    Ok, I see you wanted me to look at the other video about the hole in the fridge, not the one in this thread about the ceiling. I found it and it does help with concepts. I am going to attempt what I said in my last post and use a green screen and try to skip all the roto work.

  • I am so sorry @DataDesign... That's what I get for making the thimbnails look so similar. I went ahead and updated the link in case you still needed it however the green screen mthod woud be much faster.

  • edited June 2016


    Thanks for the update. I just tested the greenscreen idea with a door in the hallway. It worked as I had hoped. Except I was only using a room light and I guess it was too dark because the green came out all pixilated and looked really bad and could not be fixed with spill suppress or any other thing I tried. I will do it over with actual lights etc.

    I thought that you could probably do the same with your fridge shot, but by the time you got it all set up, all your food would go bad. :-)

  • Hahaha yeah, I prefer to spend more time in post than in lighting.... usually wastes more time, but just my preference I suppose.

    Have you tried following the tutorial for how to key a green screen well in HF? I can share one that helped me a lot if you'd like, because it may not be the lighting thats bad... just need to play with the settings of the effect a bit more :)

  • I recently had to do a lot of roto for a couple of short clips... I cannot see myself getting a job as a rotoscoper in the future :P

  • Triem23Triem23 Moderator

    Roto is boring and tedious and no-one likes it. There's a story Dan Shor,  the actor who played "RAM" in the original TRON told, where one day he ran into a man who said (paraphrased), "Are you Dan Shor?...I hate you so much right now. All I've done for the last year is roto your eyes."

    If you have mocha, I really suggest using that for your roto work. It will still be tedious, but mocha really can cut a lot of time off roto.

  • Aladdin4dAladdin4d Moderator

    Things I'd rather do than roto......

    1. Take a beating
    2. Shop at Wal-Mart on a day where most people just got paid.
    3. Attend a Clinton rally
    4. Attend a Trump rally
    5. Attend a Justin Bieber concert
    6. Listen to an endless loop of Chris Evans saying "Naughty" (I feel violated every time I hear him say it)
    7. Get trapped in an elevator with Piers Morgan
    8. Grow a mullet and move into a trailer just so I can be profiled in American Mullet 2
    9. Go through an IRS audit
    10. Be waterboarded
  • I'm sorry... #5 - attend a Justin Bieber concert???

    Even I have my limits... 

  • Triem23Triem23 Moderator

     Yeah, replace the Bieber concert with "Brexit." ;-)


  • It's funny. Last year my school sent us to go see some universitys so I went to a tech university and they told us about how successful their students were. "One of our students has moved on to Weta Workshops to become a roto artist" It was at that moment that I lost it...

  • Triem23Triem23 Moderator

    Here's the thing about roto--it's the absolute essential skil for VFX. If you can't roto, then stop, man, because you won't get very far. 

    It's tedious, but it's vital. However, there is a certain artist well suited for roto-- the type of person I'm just his single-minded focus on the task. Probably the kind of person who would enjoy a hand-drawn animation. There's nothing wrong with being a roto artist. It's an essential job, and a good Roto artist is worth their weight in gold. Weta? He's probably worked on a whole bunch of major summer blockbusters. You should check out his IMDb page. 

    edited June 2016

    That's true, but we all know that they're out for the cheapest paid roto artists too, so if you don't climb fast enough based on your expectations, you might just give up or go insane. Roto is certainly easier now that Mocha is so accesible though.

    Me personally. I don't care if I got to work on a Hollywood movie, I would rather clean the streets than roto all day.

    This sums it up nicely:

  • Triem23Triem23 Moderator

    Speaking of roto. If you don't have mocha, then you want to point track your footage, then parent a plane to the track and roto on the plane. Then convert the plane to a Composite Shot and use it as a Set Matte source. 

  • I like rotoscoping... :( Anyone linka tut for rotoing with mocha though?

  • Triem23Triem23 Moderator
    edited June 2016

    This is the basics. Notice that first you track, then link a second layer to do the actual roto, just as suggested with Hitfilm. Then it's exporting masked planes to Hitfilm. 

    From there you should be able to adapt any Mocha AE roto tutorial. Except we export Masked Planes to use as mattes instead of AE masks, but principles are exactly the same.  

    This is part one of a roto tutorial that really worked for me.

  • I'd suggest you watch that and the two other videos on at least 1.5 times speed. ;)

  • I want to post a video on this thread, but I don't know how. Do I have to have a YouTube channel or can I post from my home computer?


  • YouTube is an options, you can upload the video as "unlisted" so only the people that click the link can view it if you want to keep it with the HF Family :)

    Another oprion is upload to and share the link here. There is a file size cap with them of 2gb I think. Hope that helps!

  • Aladdin4dAladdin4d Moderator

    @DataDesign  You'll have to upload it somewhere there's no way to post a video straight from your computer. If you use YouTube or Vimeo all you have to do is paste the link here the forum software will recognize it as a video. You can also use cloud storage like DropBox or OneDrive and paste the link here. It won't be recognized as a video but others will still be able to get to it.

  • Thanks Triflix and Aladdin4d.

    Probably will never get around to it, but good to know now,

  • edited August 2016


  • Triem23Triem23 Moderator

    @Sarasota yeah mocha really reduces the tedium of roto. 



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