I'm working on the integration of FaceFX and IKinema LookAt Function.
If I use FaceFX Plugin for UE4, the AnimBP is simple as the screenshot <With Plugin> shown.
If I use the Animation Sequence Asset(FBX) Export from FaceFX Studio,
The second screenshot <Without Plugin - Failed> shows the failed result of animation blending.
The third screenshot <Without Plugin - Successful> is the blending method I finally found to achieve the goal.
I'm wondering why the second method was failed?
Is there any better method which can improve the pipeline or performance?
Sorry for the delayed reply, I missed this post when you initially posted it. Unfortunately, I don't have any great insights for you. I am not familiar with the IKinema LookAt Function and I don't have as much experience as you working with animation blueprints in UE4.
What I can say about the "Without Plugin - Failed" case is that there is nothing special about FaceFX-generated FBX files. If the FBX file doesn't look correct when you view it in UE4, Max, or Maya, then there may be a problem with FaceFX that we can help with. But if the the FBX file looks good there, but not when combined with your custom animation blueprint integrated with Ikinema, that's not a question that has much to do with FaceFX. It could be an issue with your blueprint or UE4.
The other point I'd like to make is that prior to today, the FaceFX animation blueprint can either be in "Add to Existing" or "Replace Existing" modes. After our release of the UE4.21 plugin today, that setting has moved to a global one in the Project Settings with an override in the FaceFX Actor's Asset Actions->Bulk Edit via Property Matrix.
The default "Replace Existing" setup has the FaceFX rest pose baked into the output. In theory, this should provide output identical to what UE4 gets when evaluating the FBX file, but it is possible that UE4 is doing something more complicated to support animation retargeting or other features.
Sorry we can't be of more help here.