I'm new to modeling in general and I have been searching for ways of solving my issue, without much success.
I have a model, which was fixed up and reduced (decimated/removed unneeded vertices, edges, faces) but in the process lost all of the shape key, vertex group, modifiers, and armature data. In essence, it is now just the meshes with the textures applied.
I was able to use Append to bring in the original model's Armature, and I parented the meshes to that, as it was done on the original, but I am unable to do anything with it as the meshes still lack all of the other data.
I have attempted to use functionality such as Transfer Shape Key, but these do not work as the mesh has changed (vertex count is no longer the same).
I can remake all of the Shape Keys by hand, I am willing to figure that out and work on it, but I am wondering if there is any way that I can copy the other data, such as vertex groups and such so that I can have the model fully rigged as it once was. I want to be able to pose the model, along with setting up shape keys again.
This is a model that is meant for a game, VRChat, and I am doing all of this to make it a game-ready model. Apologies if this question is a bit misplaced.