You should not be using h.264 for DI (digital intermediate) It's lossy, it is GOP compression, it's just not suitable. Use one of the production codecs.
That said, without knowing more about your project I'm at a loss. A screenshot of the problem area may help especially if you reveal all of the properties on the problem layer (press uu). Have you gone through the rotobrush tutorials? Rotobrush works just fine on production grade footage when applied in the right way if your disk cache and other preferences are set up properly and you have enough memory.
Hmmm, it may be the h264 output that's causing the issues. I'll try another format and see how that goes. What do you recommend for a better format when the source footage was AVCHD interlaced? I'd prefer not to use lossless AVI because of the long render times and large file size.
And thanks for the quick response!
Well, I guess that wasn't it. I just tried exporting as AVI and I still got the clipping. I've used the Rotobrush tool only about 10 times so far and it's worked well everytime I've used it in the past. The biggest issue I ever had was when trying to roto a dark object in front of another dark object (for obvious reasons). I have my disk cache set up on my SSD with 25GB reserved for just the cache and 16GB RAM. I tried both with rendering multiple frames simultaneously and only rendering one frame at a time with the same results too.
The only part that is stumping me is that it only happens when I export, but not when I RAM preview...
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Turn off RMFS (MP) when using rotobrush. Clear your cache. Show us a screenshot in the timeline with the CTI at the problem spot and all properties revealed for the layer.
I tried shutting off RMFS, clearing the cache and purging the project so far with no luck. I'll try to get a screen shot posted when I get home tonight. Thanks for the help!
I see that your source footage is still h.264, and that you changed the RENDER to an AVI. Oops.
Transcode that H.264 footage to something that's lossless, and then see what happens in AE.
I think I may have the solution for this. I solved it when I experienced the problem anyway:
try checking the quality of the preview in after effects. I think you have to work in full quality to get an accurate representation of what the roto brush is doing in after effects.
I was getting a different output in my renders (Prores 4444 with alpha) from a 4K comp. switched from half quality to Full and saw that the matte was completely different!
hope this helps.
Thanks! That actually makes a lot of sense based on what I've seen. I'll have to give that a shot the next time I use the roto brush.
use the original footage, no need to deinterlace first, interpret footage correctly, precomp if required. maybe at twice frame rate to compensate for the inter field movement...
though I agree transcoding to pro res makes it easier, the right set up can cope with native footage.
I would put a bright colour solid guide layer underneath to check where holes in the matte could be being disguised by the background colour.
Check for after effects nightmare premultiplication of layers and maybe change layer mode to alpha add in case overlapping edges are causing unwanted transparency.
always render out to an RGB codec as AE is rgb based, then compress in AME...
ALways work at full res, full size.
MANUALLY delete the cache folders as you can quite often be looking at old and corrupt caches.
I have ioFX cards which really help the smoothness of roto...
i know the answer is here but start with preferences>media/disk cashe>clear disk cashe. i was stumped for hours....and i mean hours trying everything lol but cleared cashe and worked right off the bat, so thank for everyone who threw their ideas out