Render Optical Flow

[Thanos Papadopoulos]

Thanks I’ll check it. Although I have seen this to 2 mac pro (one 2013 and one older) and one Imac 2014. But I’ll check the graphic cards.

Fix it in Pre.

[Joe Marler]

[Nikos Papadopoulos] “Usually this happens if the system has NVIDIA instead of AMD”

I have four Macs with AMD GPUs and I periodically see this problem on all of them. As soon as 10.4 is released I’ll test that.

[Bruno Courcet]

Same issue here. Sometimes it just won’t render. I have to chose frame blending or normal to have it rendered.
I’ve managed to improve it by always waiting till optical flow has completely finished being calculated before rendering. Then i’m able to render. But sometimes if i close the project and re-open it another day some clips with optical flow are not rendered and won’t get rendered, except if i choose frame blending or normal.

[Tommy Brown]

Hi Thanos

So this issue really bugged me a while back and after lots of searching I final found the answer that has been working for me ever since.

When choosing Optical Flow let it FINISH its analysis before moving on. On export yes it will be fine but in the projects I can now render all my Optical Flow clips.

Hope it helps.

[Thanos Papadopoulos]

I’ll try your suggestion.

Fix it in Pre.

[Eric Santiago]

Just to add, I had a few posts here about this issue.
Only to find that a client used the Flow transition which would not render period.
Once I removed the transitions, the project wasn’t crashing and using Optical Flow with clips were a breeze.
And yes, always let it render first before doing anything.
Learned that the hard way 😛

[Jeremy Garchow]

To add to the add, there are other processes that use optical flow like stabilization. Be sure to check if any clips have that turned on.

Sometimes you have to re add the clip to the timeline to shake loose the failed processing, but this is a rare occurence.

[Eric Santiago]

[Jeremy Garchow] “Sometimes you have to re add the clip to the timeline to shake loose the failed processing, but this is a rare occurence.”

So true. I was one of those that gave up on any digital voodoo e.g. stabilizer, optical flow, etc.. in FCPX but after that long bout of hell, it’s been a slice of late.
Mind you I still can crash FCPX with the simplest editing of titles but it’s not as bad as other NLEs when it comes to crashing.
FCPX remembers most of your work at least 😉