No one in the thread asked you to pick interpolation type. In fact I think I said don’t bother unless you are changing the type (linear, etc). You were saying you were doing roto frame by frame which won’t interpolate because it doesn’t have any frames to do any interpolating if your keys are one frame over from each other. Simply space out your keys and it will interpolate. That’s all we were saying.
Chris Smith
https://www.sugarfilmproduction.com