I've been playing around with regular sprite sheets for a few days, and I can create animations with them by displaying their frames in sequence. I'm now trying to use some sprites that I bought, but they're in a weird atlas format. Instead of frames to be shown in sequence they contain components that are meant to be connected, like upper and lower arm components meant to be connected by a joint at the elbow.
I can't find any tutorials on how to actually use these types of sprite sheets. There only seem to be examples on how to atlas (as a verb) your sprite sheet to presumably generate the txt/json files I already have.
How do I take txt/json and PNG files of component pieces, and display an animated character with moving arm components that are properly connected at the elbows and shoulders?