Iris/Oculus & GeckoLib Compat Mod FAQ
10 questions players actually ask, answered.
What does the Iris/Oculus & GeckoLib Compat Mod actually do?
It patches the conflict between shaderpack entity shadows and GeckoLib's animated models, so your custom mobs keep animating correctly instead of freezing or glitching when shadows are enabled. Without it, GeckoLib entities often lose their animation state the moment a shader renders their shadow.
Do I need to configure anything after installing it?
No, it works passively once installed alongside Iris or Oculus and GeckoLib. Just make sure all three mods are present and enabled, then launch the game with your shaderpack as usual.
My GeckoLib mob animations are still broken with shaders on. What should I check first?
Confirm the compat mod is actually loaded and that your shaderpack has entity shadows enabled, since the fix only applies when shadows are being rendered. If animations still break, test with shadows off to see whether the issue is the shader conflict or the mob's own model/animation files.
Does this mod work with both Iris and Oculus?
Yes, it targets both loaders' shader pipelines, so it covers Fabric setups using Iris and Forge/NeoForge setups using Oculus. You only need the version matching your loader.
Will this fix animations for all modded mobs, or only GeckoLib ones?
It only addresses entities animated through GeckoLib, since that's where the shadow conflict occurs. Mobs using vanilla or other animation systems aren't affected by this particular bug.
Does the compat mod hurt my framerate?
It's a lightweight patch, so the performance cost is minimal compared to the shader itself. If you're seeing drops, the usual culprits are the shaderpack's shadow resolution and the number of animated entities on screen, not this mod.
Can I use this with shaderpacks that don't render entity shadows?
Yes, it's harmless with them, but it won't do anything noticeable because the conflict only triggers when entity shadows are active. The fix simply sits idle until shadows come into play.
Why do my mobs T-pose or freeze only when shadows are on?
That's the classic symptom this mod fixes: the shader's shadow pass renders the entity without the animation transform, so the model snaps to its bind pose. Installing the compat mod lets the shadow pass respect GeckoLib's animation state.
Do I still need this mod if I already disabled entity shadows in my shader settings?
If you've turned entity shadows off entirely, the conflict won't occur, so the mod becomes unnecessary for that setup. Many players keep it installed anyway so they can re-enable shadows later without re-breaking animations.
Is this mod compatible with other animation or rendering mods?
It's designed to sit alongside GeckoLib and your shader loader without replacing either, so it generally plays fine with other rendering mods. If you stack multiple patches that touch entity rendering, test them together and remove conflicting ones if animations regress.