UE4 Live Link Facial Capture Question About Eye Tracking

Hello there,

I am currently learning how to use the Live Link Facial Capture tool that unreal provides. So far everything makes sense except for one thing. The tool provides you with facial capture data in the form of animation curves. I generally understand what each animation curve tracks. But I’m confused on the eye tracking specifically.

For example, The tool tracks animation curves that are called “Eye Look in Left” and “Eye Look out Left”. From what I can see, this controls the rotation of the eye around the y-axis. But there’s also another curve called “LeftEyeYaw” that seems to be doing the same thing but the values are significantly smaller according to the live link debugger. The same confusion applies with “Eye Look Down Left” and “LeftEyePitch”.

I wanted to know what’s the difference between the two animation curves and when do I need to use LeftEyePitch, LeftEyeYaw, etc