Animation Transfer Tool
Begin by selecting the file which has the animation you wish to transfer FROM.
This can be a simple skeleton file, an FBX or even another rig.
Next, import the destination rig where you want the animation transfer onto.
Once both have been imported the lower section of the tool will open up and allow you to change the mapping. This is a list of nodes dictating what is transferred from and what to.
The Source Root and Destination Root are the parent nodes which hold a joint hierarchy or a list of controls.
The tool will try and make a guess as to where the root joints/controls are. You can change either of these if they are incorrect and the mapping list below will update with the new hierarchy.
You can also go through and input these manually too
As you can imagine, going through a long list of joints and controls and matching them up can be a time consuming tasks, but the tool has an Auto Match function that will attempt to match them for you.
When done, the items in green should be a direct match. Ones in amber are more of a guess so you should check them and any in red definitely need double checking.
Once you are happy with the mapping I would recommend saving it, just in case you need to reload the files.
When the mapping is set, and saved, you next need to connect the source animation (skeleton or rig) to the destination rig.
There are two Transfer Types.
Rig to Rig will attempt to maintain the same animation curves on the source rig, meaning you get the same keyframes.
Skeleton to Rig will initially try to connect the source and destination using a direct connection, but sometimes this might not work correctly depending on how the destination rig is setup.
If there are issues you can check the Use Constrains box to instead constrain the source and destination.
You will notice that once the source and destination are connected, a series of yellow balls will appear.
You can use these to tweak the animation so it better fits your destination rig.
This is only currently available when using the Skeleton to Rig option, but a similar animation approach is coming soon to the Rig to Rig option.
Once you are happy to proceed, click the Bake button to apply the animation to the new rig. This will also automatically remove the source file for you.
Alternatively, if you need to make adjustments to the mapping or transfer type, you can Disconnect the skeleton/rig.