https://wccftech.com/grand-theft-auto-v-definitive-edition-overhaul/

The Grand Theft Auto V: The Definitive Edition graphics overhaul mod aims to improve the visuals of the open-world game developed by Rockstar by introducing new high-quality textures.

The mod, which is being developed by BadassBaboon, will eventually replace all of the game's environmental textures with 2K and 4K resolution textures. A comparison video that has been shared online highlights the differences with the vanilla game, which are quite big in some cases.