>>8560920
Yeah, but there are tools to make it easier. When stitching the individual frames in GIMP, you can use the Difference mode for a layer to align two parts of a stitch as best as possible. You can then use a transparency layer mask and a gradient to get rid of stitch seams along the intersection of two layers.
Stitches for scenes with diagonal panning like
>>8547890 are the devil, though. They require an insane amount of work to put together because you can't just pick two or three loops from the pan - you have to capture the ENTIRE thing and work on it frame by frame. Worse yet, you also have to deal with diagonal stitch seams, which I still haven't figured out how to fully address, given that a lot of video encoding doesn't support transparency gradients along frame edges.
Stitches in cardinal directions are pretty easy, though. Often you'll only need to take like 2-3 screenshots of every loop frame from 2-3 positions in the pan: one near the start, one near the end, and possibly one in the middle. Pic related is an example of a simple cardinal stitch. These kinds of scenes are nearly ideal for stitched animation loops.
A couple of things to watch out for:
1. The first and final loops may not encompass the whole animation.
2. The animation loop may change mid-pan.
3. The background scrolling may not match the speed of the animation.
