So I just glanced over some old post by BPR showing how to animate UVs through object color and died inside as I realized that I did it through shapekeys for years when a cleaner solution was so obvious. Anyway, I whipped out my calculator, hooked up some math nodes and got the setup working in like ten minutes, easy as goblin pie.
But there is a problem: you have to specify number of columns and rows for each spritesheet, both for the nodegroup that does the UV displacement as well as in logic properties or somewhere else where python can read it to control the animation in the standalone player (so no bpy).
One easy way out? I can add a menu where you register objects as spritesheets, set the values once and then it automatically translates the changes to all other fields. Could make it part of the spritebake thing I wrote forever ago, so finally make it an actual addon.
And so while am at it I guess I’ll just make the ultimate sprite toolbox. Anyone got any other ideas for making spritesheets “easier” to use?