The naming makes sense to me: an atlas file project-hd.atlas
has image files named after it: project-hd.png
, project-hd_2.png
, etc.
There's not a way to get project_2-hd.png
and project_2-sd.png
, sorry. If you rename the files, you'll have to also change the atlas file, as it has the file names.
Is the naming important for you? Generally you just load an atlas and it finds the image files without you needing to even know their names.