In my project, if I want to create a custom character appearance system. I define many float values that players can modify (assuming they are between 0 and 1) to control the weight of each pose asset. This is actually unrelated to which animation the specific player character plays. No matter what the player is doing, their appearance should remain unchanged. I looked at the document and said that in order for pose assets to have curves in the animation sequence, I had to add curves to each animation sequence for dozens of pose assets and set them to 1. Then, I used the Alpha of the Additive node to control the weight of each pose asset. This is very troublesome. If only it could use parameters to control weights, or rather use curves unrelated to the animation sequence.
You can and you cant.
You have to actually add the curves manually to all animations in one way or another - even as meta-data only.
After that is done, the animation has a value and you can use code to manage it.
There could possibly be an exception to it, and that is to set the Base Pose of the animation blueprint to have those curve values.
In theory, if you then blend by bone on top of it on the Root bone (maybe pelvis depends if you use root animation or not), you can replace the whole rig/armature but keep the curves you instanced active for all animations.
Keep in mind its a hack to save time, and its likely to fail eventually with engine changes… if it works at all.
It does work if you want to replace say the face of a character to add morphs to it, but thats up the chain from root…
You can drive pose assets without adding curves to any animations.
Here is an example of one way of doing it.
I’m away from my computer at the moment otherwise I’d provide more detail.