Now caves are fully bright without any pack.
If you just want to see easily in caves without cheating, the gamma edit (Section 4) is simpler and more effective than any texture pack for 1.12.2. fullbright texture pack 1.12.2
The pack is compatible with Minecraft version 1.12.2 and may not work with other versions. Now caves are fully bright without any pack
A Fullbright resource pack in 1.12.2 works by: A Fullbright resource pack in 1
Fullbright texture packs are essential tools for Minecraft players who want to eliminate darkness without cluttering their bases with torches or consuming endless night vision potions. In version 1.12.2—a golden age for modding and PvP—having clear visibility in caves, the Nether, and during nighttime raids provides a massive competitive advantage.
Installing a fullbright texture pack for 1.12.2 is straightforward. Since this version of the game is highly optimized for performance, most packs are lightweight "overlay" styles. You simply place the .zip file into your resourcepacks folder and move it to the top of your active list in the game settings. It is worth noting that for many 1.12.2 fullbright packs to work correctly, you may need to have OptiFine installed. OptiFine allows the game to bypass standard lighting engine limits, ensuring the "Internal Shaders" or "Custom Colors" settings can force the brightness to stay at 100%.