Rotobrush slows down, then stops after trying to render simple short clips in Standard Def AND 1080p

I too was facing the same issue, and trying for hours to get it working. I upgraded from After Effects v18.4 to After Effects v22 (October 2021 release), and the Roto-brush did it work superfast. Quite impressed... finally! :)(:

I am a new student at TAFE and have this issue on a 23 second (60fps) clip, but I don't see any option to download 18.1...even cutting pieces to a couple of seconds, this brush slows to a crawl, and also takes a long time updating after a brush stroke change.

Switch to 18.1! This also worked for me! And Im on a Macbook 15" i7 16gb ram, 4gb graphic.

with the latest update it took 24h to propagate a 3sec clip. And now I dont need to worry about it. This is a complete mess from Adobes side. I Don't think this is accaptable...

Thank you for posting this issue @Letty2019 . I've been fighting this all month. Wasted more time then I care to admit by dumping progress and resstarting because I thought I had messed with something inadvertantly to make it act so slow and moody. Thanks @Jordan Clay  for the solution. I couldn't find v 18.1 for some reason. So I tried v 17.7.0 which I could find and it works like it used to. Super smooth and fast. Sanity is slowly returning👍 

Rotoscoping is part of my main income workflow its absoloutley needed. I had the same symptoms. Rolled AE version back to 8.1..... This was my only fix. I tried workarounds. I tried driver updates everything. Now my roto works with 130+ frames no stuck issue like this. Believe me roll bakc to 8.1

I read dozens of blogs, and there is so much info, it's almost impossible to self diagnose this issue.

BUT.....

I thought of a simple, and when I say simple, it's so simple I'm embarrassed to write it here, but I hope this helps....

Say you have a 10 or a 15 second clip (or much more) and your rotoscope "2.0 Best" rendering works fine for the first 5 seconds, then it starts to get slower and slower and then at 10 seconds, it's a crawl, then eventually it stops.....  (roto will die when trying mask something that has a complicated busy background)

Simple Solution:

Take your clip (remove rotoscope effect first) and simply slice it up into sections.  On your timeline just click where you want a break, like the 5 second mark, then:  Cntrol + Shift + D  that will make a slice and put the rest on another layer... then do it again for the next 5 seconds.... etc...etc.... until your clip is all broken up.

Now, you can rotoscope each section.  It's better because if you have an adjustment, it's just in one section, so it won't take a hour to fix it and re render the whole thing.

If still having problems, delete the rotoscoping, and also clear your cache out, then slice and dice, then add the rotoscope to each clip individually.

Only downside, you have to make a new rotoscope for each section (no big deal, at least it works now) Make the first section your master, and copy and paste the roto settings to each section.

This works well when you have a complicated roto and are using 2.0 Best.   

Hope this helps, it did me.

Letty

How to fix the first frame of each of your new sections....

You know when you rotoscope, the very first frame stinks, and frame 2 and on is great....

OK, now that your timeline is in bunch of sections, you don't want to deal with that 'bad frame at the start of each layer, so do this:

Say you are on layer 2, just pull the timeline to the left so one new frame appears and start your rotoscope on that frame, then when done, just tuck that frame back to the right to remove it. Or you can just leave it caz the layer above will block it from being seen, depends on how you made the order to all your new sliced up layers.

Of course that works on all the new layers, except your very first layer if you don't have the extra frames there...  but all frames after will be clean and pretty and you won't be tempted to buy a $1500 new gpu when your gpu works just fine.