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Stream Motion Capture Data Live in Houdini

  • Updated

Introduction

In this article you will learn how to stream real-time motion capture data onto a character inside of Houdini

Requirements

  • Houdini 19.5
  • Axis Studio
  • Axis Neuron/Axis Neuron Pro

Axis Setup

All Perception Neuron hardware, including our legacy hardware, can stream data onto Houdini. Currently Houdini's Mocap Stream node supports UDP communication from Axis applications. Please use the following settings carefully to send data to their Mocap Stream node.

Axis Studio

mceclip0.png

Skeleton: Axis Legacy
Rotation: YXZ
Displacement: Enabled
Type: Binary
Protocol: UDP
Local Address: 127.0.0.1:7003
Destination Address: 255.255.255.255:7001

Axis Neuron/Axis Neuron Pro

mceclip2.png

Go to File --> Settings --> Broadcasting 
Select UDP
Enable BVH 
ClientPort: 7002

Installation

Houdini natively supports Perception Neuron through the MOCAP STREAM node. No additional download is needed

mceclip1.png

Setup in Houdini

In Houdini we will create geometry node and build the following node graph. This node graph will include our target character and our mocap real-time data.

mceclip3.png

  • Create a Geometry node and open the Geometry node
  • Add an FBX Character Import node. Use this node to add your character to the scene
  • Add a Mocap Stream node
  • Select the Mocap Stream node and apply the settings from Axis Software mceclip0.png
  • Add a Joint Deform node and connect the Rest Geometry slot to the FBX Character Import node
  • Add a Rig Match Pose node and have the FBX Character Import and Mocap Stream node both feed into itmceclip0.png
    • Display the Rig Match Pose node, click on theViewport and hit enter, Now you can modify the skeleton into a perfect T-pose if needed
    • Uncheck: Enable Match Bones
  • Add a Map Points node and connect it to the Rig Match Pose
  • Turn display on for the Map Points nodemceclip0.png
    • Change the target guide offset to 0.3 in z
    • Click on the Viewpoort and click enter
    • Connect all the points between the skeletons
    • under Align Guide, uncheck translate
  • Add a Full Body IK node and connect it to the Map Points node
  • Connect the Full Body IK to Bone Deform
  • Turn on the display on the Bone Deform nodemceclip2.png
  • In the Mocap Stream node, click Connect and your data should play in real time

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