Mocap Manager

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

This tutorial covers the following topics:

• Enabling the plugin

• Setting up your mocap stage representation

• Managing performers, characters, and props

• Configuring Live Link

• Recording and reviewing takes

• Creating a custom workflow

• Using Metahumans with Mocap Manager

Set up Mocap Manager

To open Mocap Manager, follow these steps:

1. In the main menu, click Edit > Plugins.

2. Search for and enable the Performance Capture Workflow plugin. When prompted, restart the editor.

3. In the main menu, click Window > Virtual Production > Mocap Manager.

   

Create the Required Data Tables

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. 

There are two data tables to keep track of your shoots — a Productions Table and a Sessions Table.

Productions are intended as the highest level container; many sessions can be created in a production. Productions can be used to organize larger efforts (such as separate games or cinematic deliveries) in a single Unreal project. They are optional — you can use the default production instead.

Sessions are a collection of folders and assets for a given shoot. Sessions represent individual capture sessions, such as a morning or an afternoon shoot. When you create a session, folders and a collection of assets used during a session are created.

To create and assign these data tables, follow these steps:

1. In the Mocap Manager window, click Create Missing Assets if prompted.

   

2. Select Yes to create these assets in the default folder (/Game/Pcap) or select No to choose a custom location.

Once you have created the data tables, follow these steps:

1. In the main menu, click Edit > Project Settings. 

2. In the Project Settings window, navigate to Performance Capture. Under Internal Database Tables, assign the Sessions and Productions data tables.

   

Use Mocap Manager

In this section, you'll step through each major section of the Mocap Manager UI and learn about what each feature does.

Session

In the Session tab, you can create and manage a capture session and generate a folder structure that becomes the active context for your shoot.

To create a new session, follow these steps:

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

2. Click + Session.

This creates a folder in your project and the session becomes active. This folder structure is created per session and is placed under the PCapRoot folder defined in your DefaultSessionTemplate asset. 

Navigate to your session folder at any time by clicking the folder icon in Mocap Manager, in the top-right of the UI.

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. 

When you create a session, Mocap Manager checks if your open level is using world partition or level streaming. Depending on the context of creation, a data layer or sub-level is created in the [SessionName]/Scenes folder. 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.

Stage

In the Stage tab, you can spawn, customize, and visually align a stage asset to match your physical mocap stage — giving you a spatial reference inside Unreal for where your real-world performers and cameras are.

The Performance Capture Workflow plugin comes with a default stage asset called BP_DemoStage that you can duplicate and edit to suit your needs. This Blueprint spawns on any valid floor in front of the camera and is added to the Current Context for your level. For easier positioning when aligning your Unreal level to your real-world stage, you can toggle the grid view and the stage ghost meshes.

Motion

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

Performers

In the Performers tab, you can 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.

   1. Alternatively, expand the Advanced section and enable Constrain Pelvis. This locks the chosen pelvis bone above the mocap system’s origin, so the performer does not need to reposition themself.

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

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

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

Characters

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

To create a character, follow these steps:

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

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.

To open the Retarget Settings window, click the retarget tuner button on a character.

Props

In Props tab, you can 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.

Dynamic Prop Attachment

By default, props are created using the DynamicPropComponent. This is a Blueprint-defined actor component which you can customize by overriding the Calculate Dynamic Offset function. You are not required to customize it, as there is already logic to govern applying a dynamic offset to a single-handed prop.

Once you have spawned the prop into your level, click the Prop Offset button to open the prop tuning panel.

Here you can set the CaptureCharacters that will handle the prop, and which bones should be tested for hand contacts.

In the gif below, you can see the final result.

Live Link

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. 

Record

In the Record tab, you can prep a slate to name your take, use the Mocap Recorder to select which actors and data to capture, and begin a recording.

Create Slates

You can 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. 

Create a 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, or audio). 

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

4. Click Stop to stop recording.

Recordings are automatically logged into a Takes Data table.  

Review

In the Review tab, you can browse your Takes Data table, inspect the recording, assign star ratings for sorting and filtering, and export the table to .csv for production tracking.

To view your takes, follow these steps:

1. Click the Review tab, then click Take View.

   

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

Create a Custom Workflow

To create a custom workflow in Mocap Manager, you first need to create a data asset. This data asset contains an array of variables that define the name of a phase, a Texture2D to use as the icon, a bool to determine if this phase should be enabled and visible in Mocap Manager, and the Editor Utility Widget to display.

Alternatively, if you want to extend Mocap Manager you can simply duplicate and add additional entries to DA_MocapManagerDefaultWorkflow, at the following location:

/PerformanceCaptureWorkflow/Core/DA_MocapManagerDefaultWorkflow

To create a custom data asset, follow these steps:

1. In the Content Browser, right-click and choose Virtual Production > PCapDataAsset.

   

2. In the Pick Class window, select the class PCapWorfklowCustomization and click Select.

   

  This creates a new data asset of the type PCapWorkflowCustomization.

To create an Editor Utility Widget, reparent it to the EW_PCapPanelBase class, and update Project Settings, follow these steps:

1. In the Content Browser, right-click and choose Blueprint > Editor Utility Widget.

   

2. In the new window, open the Graph Editor and select Class Settings. In the Details Panel, click the dropdown next to Imported Namespaces and select PerformanceCapture.

   

3. In the main menu, click File > Reparent Blueprint.

   

4. Search for and select  EW_PCapPanelBase.

   

   Only Editor Utility Widgets parented to the EW_PCapPanelBase class can be selected in the Workflow Customization asset.

5. In the main menu, click Edit > Project Settings. Under Performance Capture, next to Default Workflows, assign your data asset.

   

Prepare a Metahuman (Optional)

On Fab, you can find a plugin to integrate MetaHumans with Mocap Manager with scripted action to convert a MetaHuman Blueprint actor to a CaptureCharacter Blueprint.

To manually 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.