Since upgrading to 10.4 from 10.3.4, optical flow no longer works. I am working in Prores HD footage, on High Sierra.
I have a partition drive with optical flow running el captan and 10.3.4 and optical still works in that.
I've tried a couple of the solutions which are delete optical flow renders.
What I get when I change the setting from frame blend to optical flow is that in the render queue, it says its trying to render it but it's just stuck at the beginning of the render. Any thoughts? Help?
I'm not having any issues with OF in macOS 10.13 or FCPX 10.4. When you change your quality setting from Frame Blending to Optical Flow, and analysis takes place. The complexity of movement in that clip, and its duration determines how long the analysis will take. But, "rendering" doesn't automatically trigger when enabling OF. Again, on my home Macs and the Macs in our TV station, none have this issue. Are you talking about "renders" or "analysis" files you're deleting? How much are you slowing the clip down by?
Again, works fine on the dozen Macs I manage. Did you reset preferences? Did you delete all render files via file menu? Trying to figure out what's going on with your specific system, or what would cause such bug. Any 3rd party plugins used on the clip you're trying to so slow motion with?
I would like you to do a test in order to narrow down the possible causes. Create a new admin user. Log in with the new user, launch FCP X and try OF and exporting to PR4444 in FCP X. Does this solve the issue?
If this does not solve the issue: are you working with XDCAM media?
I just had this issue and fixed it, at least for me.
Turns out the clip I was trying to slow down with optical flow as 50p but was made from was seems to be 25p source material. When you set speed to automatic on a 25p timeline it plays at half speed (50%) but stuttery. Optical flow had no effect. In fact what happened was it would seem to analyse the clip, but then if you tried to render it was just stuck at 0%
But if I first exported the clip from the timeline effectively baking in the 25fps then brought it back into FCPX, set it to half speed and applied optical flow it worked as it is supposed to. Hope this helps someone.