This Retarget Animation tool makes use of the character system in MotionBuilder, as well as additional components that can be defined within the tool, to retarget animations from one character skeleton to another.
As a general practice, it is important to note that optimal character settings will differ as you retarget from one character rig to another. It is recommended that you merge both character rigs into a scene, optimize the character settings for your retarget character rig, and save out the retarget character FBX file before batch retargeting. This tool assumes that all character rig files have been set up in this manner.
First, select a folder from which to retarget animation, as well as the character rig to retarget animation onto.
To batch all FBX files in the selected folder, check the 'Batch Retarget' option. If retargeting a select number of files, you can select a specific file by clicking the 'Add Entry' button, and selecting said file in the created widget:
Each widget consists of a dropdown, containing all FBX files found in the selected motion file folder:
Additionally, all entries are selectable with a mouse click. A selected entry is highlighted:
and can be removed from the list with the 'Remove Entry' button. The 'Remove All' button will clear out all entries.
MotionBuilder character retargeting only supports retargeting animation onto the core body joints of a character rig. If there is a need for additional joint retargeting (such as attachment joints, extra limbs or tails, etc.), you will want to make use of the 'Extra Components' option.
Once enabled, you can select to retarget finger animation, and/or create new retargeting components.
To create an additional retarget component, click the '+' button. A supplemental UI will pop up:
To begin, click the 'Prep Scene' button. This will create a new scene in MotionBuilder, composed of the desired retarget rig as well as a motion file from the selected motion file folder. In this scene, identify the retarget rig joint, as well as the joints on the original motion file char rig that should be driving it (aka source joints). You have multiple options regarding how you want your source joint(s) to drive the selected retarget joint:
- Rotation: supports single source joint; Source joint's rotation will be transferred to the retarget joint.
- Direct Parent: supports single source joint; Source joint will directly drive the selected retarget joint.
- Rigid Bodies: supports multiple source joints; Source joint positioning will cumulatively drive the selected retarget joint.
Once you have identified the retarget and all source joints, click 'Add Component'. You will see the extra retarget component listed on the main UI of this tool:
After creating any and all additional retargeting components, identify which folder all retargeted motion files should be saved into, as well as FBX version type.
All retargeted files will be saved into the specified delivery folder, with a prefix of the selected retargeted char rig appended to their file name, and the version type FBX (specified in the dropdown at the bottom of the tool) as a suffix.
Ex: if the move was called 'magic_attack.fbx', the FBX version type was 'Current' (2018), and the move was retargeted onto a demo character rig named 'demoChar.fbx', the retargeted motion file will be named 'demoChar_magic_attack_2018.fbx'.