2. Setup the Blueprint
Step 1.Double-click the animation blueprint in the content browser to open its editor.
Step 2.Right-click the animation graph, then create a new "OptiTrack Skeleton".
Step 3.Right-click the animation graph, then create a new "Get Streaming Client Origin" and connect its output to the Streaming Client Origin.
Step 4.Right click the animation graph, then create a new "Get Source Skeleton Asset Name" and connect its output to the Source Skeleton Asset Name.
Step 5.Connect all of the nodes together. Specifically, drag the person icon in the "OptiTrack Skeleton" to the person icon on the "Final Animation Pose".
Roll Bone Interpolation
For characters with unmapped shoulder roll bones, the skeleton plugin will detect its existence and apply a slight twist to the roll bones to keep smooth swinging motion on the arms. In the OptiTrack Skeleton blueprint, you can enable/disable this feature from the Roll Bone Interpolation checkbox, and you can also adjust how much of twist is applied by setting the Roll Bone Blending parameter. When this parameter is set to 0, the plugin will not adjust the roll bone motion, and when this is set to 1, the plugin will attempt to adjust its motion to keep the shoulder steady on the character.
Please note that this feature may not work on some characters.
3. Assign Bone Mapping
Step 1. Select the OptiTrack Skeleton plugin in the blueprint graph area.
Step 2. Drop down the Bone Mappings property in the Details Pane.
Step 3. Click “Auto Fill Bone Mapping” to automatically assign the bones in the skeleton to the OptiTrack skeleton names.
Note: There is no standard for bone naming conventions, so bone names may vary depending on characters. After doing the auto-fill, review the list and double-check that the auto-assigned names are correct. You may need to manually use the drop-down menu to adjust the assigned mapping for missing, or incorrect, items.
Step 4. Hit "Compile" in the top left to build the blueprint.
Practically, this means that you will need to do things like turn off the toe mapping for characters with high heels, adjusting the pelvis bone in Motive or in the model for characters with non-anatomical hip bones, and not use bipeds that are too anatomically different than humans, such as a gorilla or swamp monster.
For example, the character sample below has both a non-anatomical pelvis and high heels. It is preferable to use character models that are more anatomically correct, but in this case, you can do a couple things to mitigate these issues:
In the example below, since this character is wearing heels, any actor providing data for this model will also need to be wearing heels. To get around this you can just turn off the toe mapping in the OptiTrack Unreal Engine Skeleton Plugin.
