The SteamVR plugin over at unity has a bunch of default poses that it blends between on the animation side. IE: a default hand pose for gripping each object, then it blends in the current finger Curl values of the Index controllers with an open hand pose. When no object is held I believe that it just uses the hard finger skeletal transforms instead.
Their poser doesn’t “live solve” geometry or deal with any position poses (as far as I know its all snap grip based), it just blends pose states. Though I do think they have a manual poser in it so you can create poses in engine and save them out for use.
In UE4 that is fairly simple to achieve, you can pass out a “grip pose” animation from the object and apply it in the AnimBP. The reason I don’t have an example of in the template is because I honestly just don’t have any hand animations to use for it. I was considering adding an interface query to get the suggested pose from the gripped object, but its something I have mostly felt was better handled on the users end as they may end up wanting it very complex and any default implementation may not be enough information.
Letting the end user poll for the requested animation pose themselves with a custom interface is likely better in the end.
Yuri I believe has a hand posing plugin available on the marketplace (VR Hands Solver), I haven’t tried it myself so I won’t vouch for it but you can look at it and see if it meets your needs for that part as well. It uses a custom skeletal mesh though which means it will be a bit incompatible with some things.