Learn how to add natural, randomized eye blinks to your MetaHuman characters in Unreal Engine using the Runtime MetaHuman Lip Sync plugin’s Auto Blink helper. This tutorial covers calling the update function from the Face Animation Blueprint’s Event Graph and wiring the blink values into the Face Control Rig in the Anim Graph for lifelike eye behavior with no manual animation authoring required.
https://dev.epicgames.com/community/learning/tutorials/qEq2/fab-adding-automatic-eye-blinks-to-metahuman-in-unreal-engine