Mocap Manager

This tutorial provides a complete walkthrough of Mocap Manager, part of the Performance Capture Workflow Plugin in Unreal Engine.

It covers enabling the plugin, setting up your mocap stage representation, managing performers, characters and props, recording, and reviewing takes, all in support of a full performance capture pipeline.

Set up Mocap Manager

Enable the Performance Capture Workflow Plugin

1. Go to Edit > Plugins.

2. Search for and enable the Performance Capture Workflow plugin.

3. Restart the editor when prompted.

Open Mocap Manager

1. Go to Window > Virtual Production > Mocap Manager.

Create Required Assets

1. If prompted, click Create Missing Assets.

   

2. Confirm storing them in the default folder: Content/Pcap.

Instead of clicking the Create Missing Assets button, you can also manually create the session and production tables. In the Content Browser, go to Add > Performance Capture > PCap Datatable and create one table with the Session Struct and one with the Production Struct. In Project Settings > Performance Capture, set a reference to these two new tables.

You only have to add these assets once in each project where you enable the Performance Capture workflow plugin.

You might also want to create your own session template to define how session folders are created. You can do this by going to Add > Performance Capture > PCap Dataset and choose the session template type. Alternatively you can duplicate the default session template asset and modify it to your needs (/Plugins/PerformanceCaptureWorkflow/Core/DefaultSessionTemplate).

Use Mocap Manager

Mocap Manager is a centralized location for controlling what is needed during a mocap shoot. It is designed to lead you through the process linearly, from start to finish.

Create a Session

1. In the Create New Session section, enter a session name and any optional notes.

2. Click +Session.

A folder structure is created and becomes active.

Navigate to your session folder at any time by clicking the folder icon in Mocap Manager.

Productions can be used to organize larger efforts, such as separate games or cinematic deliveries, in one Unreal project. They are optional and if you do not wish to use them, the default production can be used.

Sessions represent individual capture sessions (such as a morning or afternoon shoot). When you create a session, folders and some assets used during a session are created.

Session templates allow for customization of folder structure and naming using dynamic naming tokens.

All actors created by Mocap Manager are assigned to a data layer or sub-level for your session. Each session gets a new data layer or sub-level. 

Mocap Manager checks if your currently open level is using world partition or level streaming when you create a session. In the [SessionName]/Scenes folder, a data layer or sub-level will be created, depending on the context of creation. This data layer or sub-level will be the edit context for your level. This means that all actors will be placed inside this context.

Set Up the Mocap Stage in Unreal Engine

The Performance Capture workflow plugin comes with a premade default named BP_DemoStage. You can duplicate and edit this BP to your needs.

The stage is spawned on a valid floor in front of the camera. Move and align it to your real-world capture space.

In the Stage tab of the Mocap Manager, you can toggle grid view and the stage ghost meshes for easier positioning to align your Unreal level to your real-world stage.

When you spawn the stage, it will be added to the Current Context for your level.

Motion Actor setup

In the Motion tab of Mocap Manager, you can configure Live Link subjects and create performers, props, and characters.

Live Link Preview

In the LiveLink tab, you can toggle which of your incoming Live Link subject data is displayed in the preview. The icons in the list indicate the data type: skeletal mesh, camera, or markers.

You can choose to show individual subjects or all by clicking the Show/Hide icon. 

Create Performers

In the Motion tab of Mocap Manager, click the Performers tab to create and spawn performers. Performers are encapsulated in a data asset called a PCapPerformer. 

To create a performer, follow these steps:

1. In the Create Proportioned Mesh section of the Performers tab, select a Live Link Subject from the dropdown menu. Only subjects with the role type "animation" (skeletal data) will be listed on the dropdown. 

2. Click Launch Workflow to launch the Create Proportioned Mesh viewport.

   

3. In the viewport, align the skeleton over the origin (the pelvis at (0,0)) by asking the performer to move their position until they line up.

4. Optionally, you can press pause to freeze the animation, allowing your performer to relax from holding their pose over the origin.

5. Click Create Mess & IKRig. This closes the Proportioned Mesh viewport and takes you back to the Mocap Manager panel.

6. Click Create Performer to generate the PCapPerformer data asset.

The performer will now be selectable from the Spawn Performer section. Click Spawn and the newly created skeletal mesh with Live Link data applied will spawn, parented to your Stage Root actor. 

Create Props

In the Motion tab of Mocap Manager, click the Props tab to create props for your performers to use.

To create a prop, follow these steps:

1. In the Props tab, click Launch Workflow to open the Create Prop viewport.

   

2. In either the Static Mesh or Skeletal Mesh dropdown menus, select a mesh for the prop.

3. In the Subject dropdown, select a Live Link subject.

4. In the Prop Offset section, make adjustments to align the mesh and the subject.

5. In the Name Override field, enter a name for the prop.

6. Click Finalize. This closes the Create Prop viewport and takes you back to the Mocap Manager panel.

7. Click Create Prop Asset to generate the PCapProp data asset.

You can spawn this prop into the level, same as the Performer data asset, by selecting it from the picker and clicking Spawn Prop.

Optional: Prepare a Metahuman

To prepare a Metahuman for the Mocap Manager, follow these steps:

1. Create a Blueprint derived from CaptureCharacter.

2. Copy the necessary skeletal mesh components and grooms from your Metahuman Blueprint into the new Blueprint.

3. Disable decals on all the components.

4. On all skeletal mesh components attached to the root, apart from the head, add a Follow Leader Pose node in the construction script to force these components to get their pose from the root component.

5. In the Performance Capture section of your Blueprint, untick Force All Components to Follow Leader.

Create a Character

In the Characters tab of Mocap Manager, you can create characters for your performers to control.

1. In the Create New Character Asset section, enter the following information:

   1. Source Performer Asset: Select the performer that will control this character.

   2. Character Class: Select the default CaptureCharacter class, unless you are using a custom Blueprint, such as the one from the Metahuman example above.

   3. Character Mesh: Assign the body skeletal mesh for the character. This is required for retargeting.

   4. Character Name: Enter a name for the character.

2. Click Create Character Asset. A character data asset is generated, storing references to the performer, retarget asset, IKRig, mesh, and CaptureCharacter class.

3. Click Spawn Character to spawn your character in the scene. 

When you spawn your character, it will be attached to the Stage Root actor.

Tune Retarget

Click the retarget tuner button on a character in Mocap Manager to open the Retarget Settings window. In this window, you can modify retarget properties on each bone chain. Retarget tuner is designed to work only with Humanoid Bipeds, as its chains are named specifically to match those created by auto IKRig scripts.

Mocap Recorder

Create Slates

Predefine your recording names using slates with name and metadata. This also provides facility for a checklist to work through during a session.

To open the Slates tab in Mocap Manager, click the Record tab, then Slates.

Slates are stored in a data table. You can import updates using .csv files. 

Click Prep on your chosen slate to use this name for your text recording. 

Recording

To record mocap in Mocap Manager, follow these steps:

1. Click the Record tab, then click Mocap Recorder.  

   

2. Select which actors and data to capture (performers, props, live link, audio). 

3. Click Record to start recording. The rest of the interface locks down while recording.

4. Click Stop to stop recording.

Review Panel

Recordings are automatically logged into a Takes Data table.

To view your takes, follow these steps:

1. In Mocap Manager, click the Review tab, the click Take View.

2. Under Takes Data, double-click a take to open it.

After opening a take, you can scrub, preview, and inspect the recording. Assign a rating of 1 to 5 stars for sorting and filtering.

The takes table can be exported to .csv for further production tracking.