Since 1.12.2 uses the (pre-1.14 light overlay system), the Fullbright effect is achieved by editing lightmap files, not shaders.
Fullbright Overlay 1.12.2.pack.mcmeta and assets/ folder inside.Fullbright Overlay 1.12.2.zip..minecraft/resourcepacks/.Go to Options > Resource Packs . You will see "Fullbright 1.12.2 (Updated)" in the left column. Hover over it and click the arrow to move it to the right column. minecraft 1122 fullbright texture pack updated
No mods required. No OptiFine needed (but works perfectly with it). old lighting engine Since 1
Critical for mining and speedrunning. It allows you to see every ore, mob, and ravine floor as if it were midday. Key Features Create a folder named Fullbright Overlay 1