Why does my Optimum Realism look flat or matte
The pack's PBR materials only render with a LabPBR-compatible shader. Without one, you see flat vanilla lighting on the higher-resolution textures.
Still seeing it?
Which shader did you install?
That's a LabPBR-compatible shader — it should be working. Check the shader settings: Shaders → Settings → Resource Pack should be set to LabPBR 1.3. Some shaders default to "SeusPBR" or "OldPBR" which can't read our textures.
That's why. Those shaders don't read LabPBR specular maps, so depth and reflections won't show on the pack.
Open Minecraft → Options → Video Settings → Shader Packs. The active one is highlighted at the top.
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