Many players prefer using alternative performance-boosting mods like Phosphor , FoamFix , or BetterFps on forge instances, which can conflict with OptiFine's rendering engine.
Here is everything you need to know about finding, installing, and using a 1.12.2 fullbright texture pack without relying on OptiFine. How Fullbright Works Without Mods fullbright texture pack 1.12.2 no optifine
If Minecraft highlights the pack in red and claims it was made for a newer or older version of the game, the pack's pack.mcmeta file has the wrong format number. For Minecraft 1.12.2, the correct pack_format number is . You can still force-load the pack by clicking "Yes" when prompted, and it will often work perfectly regardless of the warning. Gamma Settings Override For Minecraft 1
Some older PCs handle the raw vanilla engine better than OptiFine’s modified code. However, you have two reliable "no Optifine" workarounds
However, you have two reliable "no Optifine" workarounds that provide the same effect. 1. The Gamma Edit (No Files Required)
Certain resource packs use "core" techniques to force maximum light levels without needing the Optifine lighting engine.