Masks change position when rendering

[Mylenium]

Are you sure you rotoscoped in a square pixel comp or at least used the aspect ratio correction for the comp preview window? I’ve fallen into this trap a few times myself, so it may be worth checking this.

Mylenium

[Pour Myl

[Frank Ruggiero]

i found that sometimes i have that problem as well when i render out the finished roto with fields. since you cant see each individual field in the timeline it looks ok on ram preview. but when you render with fields there is shifting, because your mask is not lining up (because you did not roto each field.)

usually we deinterlace the footage first and work with that footage. or ill take the original 29.97 clip and put it in a 59.94 comp and roto it in there (now i see every field.) then ill put that comp back into a 29.97 comp and render.

hope that can help you figure a solution.

-frank

[Sam Moulton]

this is the same thing i’ve found. I always now roto at double the frame rate when working with interlaced video. all you have to do is open up the comp settings and type *2 after the listed frame rate, then when you’re done type /2. You must separate fields for this to work. I’ve never ran into the problem of the par causing trouble but then I never do any actual work with par preview turned on because i beleive the warning

[Jmriquel]

thanks guys, i tried doubling the frame rate of the comp to do the roto and now everything looks ok when i render…. ya save my day!