Animation Skeleton Standards?

I had assumed the UE4 Mannequin was standard in Unreal world but it seems like a number of different packages (mocap such as radical, market place characters, character creators, etc) that don’t conform to same naming or basic structure. Same with facial expressions and using the Unreal iPhone app. The retarget works as long as there’s not much of a difference and there’s nothing added to a socket.
Am I overlooking something? Are there standards or conversion skeletons to make the process better/easier? Or does everyone just try to rename each bone and or rebuild the skeleton?
Does character creator 3 produce compatible skeletons and facial or do those all need to be reworked?

Compatible with iPhone? The iPhone thing itself gives you a mesh to use i believe. You just need to re-shape the base to fit your needed face. Which is easier than applying morphs later for all 32plus things.
I think maybe blender has a function (more likely an addon) to transfer morphs. Either way, custom work.

As far as the mannequin goes, unless the marketplace guidelines changed again the skeleton nomenclature must follow the default mannequin skeleton.

Paragon characters may be an exception to this naming wise, but re-target fine. Sockets shouldn’t matter. You can really save an added item? Persona being just a preview. You should likely close that and the animation before retargeting.

Some programs have different options to support different engines. Anyway the main difference in all of them is the placement of the twist bones and their parenting.

What matters more than names is Rotations of the bone (starting pose), and its hierarchy.

Livelink (at least how I’ve learned to use it based on videos) has naming of different facial features. Matt Workman did a whole video on how to translate to match another character face so built an entire blueprint that is nothing but a 1 to 1 correspondence to a different face with different naming.
Unreal provided a special character with full facial for some of their special training. This character had cloth draped over and retargeting wouldn’t work.
Radical is a AI based mocap web set. They provide a retarget skeleton so you can’t simply apply it to another character directly but most go through the retarget even if character matches the unreal standard.

Houdini latest update video shows their rig matching where they make it very simple and fast to match skeletons regardless of naming, size or proportions. It’s all visual instead of having to type in every bone name.

Well there has never been a “standard” as to naming convention or hierarchy construction but there has been advancement in control features that has made animation management much easier. For example Motionbuilder works based on the ability to characterize a rig in such a manner that different means of control can be added to the hierarchy by extension. An auto rig for example can be applied were animations can easily be re-targeted from one character to another with in the same environment. Relationship constraints can also be built where the use of MoCap APIs can be attached with ease and the hardware supplier usually supplies as a drag and drop option.

As an opinion I believe this is the direction Epic is heading as far as their basic Epic rig goes as feature additions like re-targeting and auto-rig features makes little sense as to being able to animate with in UE4 as compared to the ability to characterize “any” rig imported into UE4 regardless of the naming convention used.