View Full Version : working on film with masks

04 April 2003, 07:40 PM
one of our fellows told me today he was workin on down sized footage proxy(originally 2k * 2k scanned film) and masked some thing and that he'd later on resize to the original footage.
although he did scale the mask up in the first frame(after upsizing) the mask did not necessarily match in many other frames thus having completely roto from scratch sometimes.

i'll summarize just in case.

1).2k * 2k made into a proxy of a smaller size.


3).restored to original size to send the rendere to the flame.

4).mask mismatch in many frames :annoyed: .

any solutions/issues.Should he just cache the shot to disk :eek:
and work from there.

thanks for any input.
oh and by the way he did mention that the flame could do this kind of thing without any problems.Would importing the workspace in flame halp any ???.


04 April 2003, 10:35 PM
Is the mask mismatching on all frames? I'm just wondering if its a framerate thing instead of a size thing (pulldown?) or alternatively, is it a pixel aspect ratio problem?

04 April 2003, 08:21 PM
hey chris,
nah... the mask is scaled to match the first frame and satys ok for some frames but goes ballistic on other frames :shrug: .I guess caching the footage to disk might be the only option then :eek: .


04 April 2003, 08:17 PM
I've had similar problems with animating masks. I've found that if I have a lot of control points and I've animated them, then it causes combustion to go "ballistic" as you say, sometimes it would even add points to my mask. The way that I've worked around it is to just make a simple garbage mask with as few points as possible for the majority of the shape and then apply a paint operator and paint out the alpha for detailed areas. I don't know if this will help you at all but I hope it does.

04 April 2003, 09:13 PM
thanks ooga,
nice idea...i guess next time.we redid the whole thing in flame.

04 April 2003, 12:17 AM
no problem. sorry I didn't help. maybe next time. cheers

04 April 2003, 06:01 PM
I've had some wierdness with rotoscoping masks in C2 aslo, and I always work at 2k. Because of this I never roto with proxies. Instead I use the real thing and save my comp about every 10 frames or so.

Alan Bell

04 April 2003, 05:51 PM
thanks for your input alan.
what if i work with HI-rez and use the crop tool to only include the areas i'm concerned with...will that reduce the load on C2 ???
i mean does C2 still calculate for the entire footage regardless.
I guess i'll just have to try but if it does work... ohhh boy zion's where the party's gonna be. :scream: :D .
In that case it'd be cool to have a crop operator so that i could probably track the crop tool with a rough pass on my subject and then get to work on rotoing at full rez without C2 calculating for dead pixels :) .

thanks for ure input.

04 April 2003, 08:37 AM
I don't know but I love to hear how it works for you. I'm about to start a very big job. I think.


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