Because it only alters light levels rather than high-resolution textures, it has zero impact on FPS.
In versions , Mojang changed how lighting shaders work, making texture‑only Fullbright harder to achieve (you often need OptiFine or a mod). So 1.12.2 is one of the last vanilla versions where a pure texture pack can give you Fullbright. minecraft 1.12.2 fullbright texture pack
There's a well‑known piece from a Minecraft modding/tutorial site (like Minecraft Forum or Planet Minecraft ) titled: Because it only alters light levels rather than
It sounds like you're looking for something specific around and a Fullbright texture pack — likely to illuminate dark caves/areas without needing torches or night vision potions. Essential Features of Fullbright 1
The is a utility tool designed to eliminate darkness by setting light levels to maximum across all dimensions. Unlike standard resource packs that change block aesthetics, Fullbright modifies light data to ensure caves, the Nether, and the End are perfectly visible without torches. Essential Features of Fullbright 1.12.2