Hey there @ViaCognita! The native sprite extraction only has two methods, automatic and grid based. Generally automatic can work if you don’t have any islands as part of one sprite, but in your case that won’t work. Grid based is usually what’s recommended if your sprites are uniform, however in your case that won’t work either.
I would recommend using an external program like Aseprite (free if you build it from source) to manually grid the sprites so atlasing is easier in engine or prepare them in aseprite then extract via a tool like FreeTexPacker, an older tool that can pack to UE file types if you’d like.
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