the item models can be changed using predicates in a resourcepack, this is a vanilla feature. Entity textures are sorta hardcoded, so it's really difficult to change them (except for the random texture variation that is applied if a texture pack has multiple textures for the same entity).
I want INFINITE possiblities of variants for EVERY item.
And i also need custom entity models / texxtures.
I want this beacuse i have a server, where i want to add a lot of items and entities (magic staff, red dragon for example) and using predicates in a resourcepack is not an option for me (entities can't be customized in that way and i'm really limited with items).
I don't want to install a mod on my server (i want the server to be playable without mods, but this mod will be highly recommended to use).
I can't just use a mod and i don't want, beacuse
- i can't add new things without client mod updates (in this way, only resourcepack update is requeried)
- i will lose a lot of players, beacuse they can have a cracked client, that don't let you install mods or they just don't want to install mods
And i'm also thinking about creating a custom client (and using no server mods, only nbt tags, used by this mod).