Xsens MVN Analyze/Animate, developed by Xsens, is the main software tool for interfacing with the MVN inertial motion capture suit. MVN Analyze/Animate allows the export of motion capture data to third party applications, making the data available to drive rigged characters in animation and more. The data transfer to other applications is primarily file-based (export) when using MVN Analyze/Animate.
However, in many scenarios, it is attractive to keep the ease of use of MVN Analyze/Animate, but still being able to receive and process the motion capture data in real-time in another application, even on another PC, possibly physically remote from the MVN system.
To this end, MVN Analyze/Animate can act as a server on a network and stream motion capture data in real-time to a client PC running a client application. This document specifically treats the use of a network streamer to stream motion capture data in real-time into the Unreal Engine.
Note: In this workflow, we assume both MVN Analyze/Animate and UE4 are properly installed and the user has a good overall knowledge of working with both programs. Throughout the workflow, pictures are placed AFTER the corresponding text.
1.1 What's improved in this release?
The MVN Unreal Live Link plug-in has been updated to support UE4 version 4.22.
1. Go to the Epic Store Launcher
2. In the Download the Unreal Marketplace search for MVN Live Link and download the plugin.
3. In the Library, Go to Vault to install the plugin to the engine version you use for your project
4. Create a new project or open an existing project.
5. Now copy the file named “MVN_remap_example.uasset” from the engine folder (e.g. C:\Program Files\Epic Games\[Engine Version]\Engine\PluginsLiveLinkMvnPlugin\Content) folder to your project’s content folder. (e.g. C:\Users\[UserName]\Documents\Unreal Projects\MyProject\Content)
6. Go to Edit > Plugins > Installed > Animation Here you should see LiveLinkMvnPlugin. Make sure to enable the plugin.
3. GETTING STARTED
3.1 Setup MVN
1. Open MVN Analyze/Animate
2. Open an MVN file or MVNX file or use the MVN suit in a live setup
3. Go to: Options > Network Streamer
4. Add a target destination (with default values: Host 127.0.0.1, Port 9763, Protocol UDP
5. Select a format that the UE4 Live Link plug-in will interpret properly: “Position + Orientation (Quaternion)”
6. When running UE4 on another PC, input the IP-address of that PC in the Host field. If it is the same PC as where MVN Analyze/Animate is running, you can just leave it at the default ‘127.0.0.1’ = localhost).
3.2 Setup UE4
1. In the Project, Go to Window > Live Link to enable the Live Link Panel.
2. In the Live Link Panel Add a Source > Xsens Live Source and make that the Port number is the same as set up in MVN (step 3.1.4)
3. Import a rigged character into the project
a. Under Mesh, make sure that you have Skeleton set to "None"
b. Under Miscellaneous, set Force Front XAsix to "Checked"
4. If your character is not in a TPose and facing the X-Axis you will need to do an extra step. Create an “Animation Composite” by right-clicking in the folder of your character and go to “Animation > Animation Composite” and select the skeleton of your character.
5. Name and open this animation and go to “Create Asset > Create Animation > Current Pose”. This will create a 1 frame animation with the pose you require. If you need to adjust it, you can open this animation and change it. Once the character is in a TPose and facing the X-Axis, press Add Key and Apply to update the pose.
6. Open the “MVN_remap_example” (Placed there earlier) in the Content folder. Then, In the Details tab, click on “RemapDict”. You will see the names of the MVN segments (Left) and where you will need to fill in the corresponding segments of your character (Right). If you do not have a matching segment put “None” (this is also done automatically if you leave it empty).
NOTE: If the actor does not have the same segment names as the MVN actor you will need to add a retarget asset. For this, you can edit the one provided with the plugin.
7. To find the segment names of your character, open the Skeleton that belongs to this. On the right-hand side in the skeleton tree, you will find the names of the segments.
8. Once all segments are filled in, press Compile and Save.
9.. In the "MVN_remap_example" make sure “Class Defaults” is selected. Now you can add the 1 frame animation you just made for the TPose Animation.
10. Now create an animation blueprint for your character. In the Content Browser, Right-click in the folder you want to create the “Animation Blueprint” and select “Animation > Animation Blueprint”. Do not select a parent class, but do select the skeleton of your character for the target skeleton. Then click OK.
11. Name the Blueprint and double click to open it.
12. In the AnimGraph, right-click and add a “Live Link Pose” and give it a subject name between 1-4 (depending on which actor you want to display from MVN, if you have a single actor file type 1)
13. Select the Live Link Pose node just created and in the "Details" Window, you can select the retarget asset you've set up earlier (MVN_remap_example)
14. Now compile and save the “Animation Blueprint”. Use this Animation Blueprint in your scene.
4 ADVANCED FEATURES
To use props attach them to one of the bones that is in the retarget manager. For example to the left hand. The prop is retargeted in the same way as the body segments using the names Prop1 to Prop4. The props in the stream will always start at Prop1 even if you disabled prop 1 in MVN and are using prop 2.
In the TPose, swords have to be placed with the tip pointing towards the x-axis and guns have to be placed pointing downwards.