I have a very low-poly model with an armature, animated with 4 key-frames over a cycle that I want to repeat seamlessly and smoothly. In Blender itself, I get a mostly smooth rotation, but with a slight hesitation at the repeat.
I've seen a video that suggests "altering the f-curve to linear rather than Bezier", but have failed to find how to achieve that.
See the way the motion slows, stops and resumes as the right foot reaches the top of the stroke (reduced frame rate to make the hesitation more obvious):
Also, when I export the model as a .dae for its ultimate use in SceneKit, the circular nature of the motion is lost and I'm left with linear interpolation between the keyframes (90 degrees of rotation each). Possibly the solution is the same for each problem? Or do I need every frame to be a keyframe?