Convert clip to 59.94 fps

I am very new to FCPX, sorry. When I have a clip in fcpx at 29.97 fps, I can not find a way to convert it to 59.94 fps. The Clip Information box (upper right) does not show MODIFY in the lower right corner. I have tried many things by searching the web but nothing seems to work. I want to interpolate a new clip to help smooth some pans in 4k.
I'm on a 2017 iMac pro with FCPX 10.4.10.
I would aslo be open to a outside program for converting before importing to fcpx. Or a plugin?
Please give me some suggestions.
Thanks very much,
Dave

davecar52 wrote: I am very new to FCPX, sorry. When I have a clip in fcpx at 29.97 fps, I can not find a way to convert it to 59.94 fps. The Clip Information box (upper right) does not show MODIFY in the lower right corner....I want to interpolate a new clip to help smooth some pans in 4k...

- File>New Project>Use Custom Settings, manually enter 59.94 fps
- Import clip and add to project or copy/paste clips from current 29.97 timeline
- In new project select clip or clips
- In Video Inspector (CMD+4), scroll to bottom, under Rate Conform>Frame Sampling, pick Optical Flow.
- If not using background rendering, render timeline to cache by selecting clips with CMD+A and render with CTRL+R.

Above procedure will maintain the same clip duration and same rates of subject motion, panning, yet will use optical flow techniques to interpolate a new frame in between each original 29.97 frame.

Optical flow methods have a significant CPU cost and render time. It can sometimes produce bending or warping artifacts so you must closely examine the footage.