NatNetToOIGTLIO

A C++ application that bridges NatNet motion capture data to OpenIGTLinkIO for real-time tracking communication with medical imaging software like 3D Slicer.

Requirements

Dependencies

• VTK (Visualization Toolkit)
• OpenIGTLink - Communication protocol for medical imaging
• OpenIGTLinkIO - I/O library for OpenIGTLink
• NatNet SDK - OptiTrack's motion capture SDK (included in project)
• TinyXML2 - XML parsing library (included in project)

Project Structure

NatNetToOIGTLIO/
├── main.cpp                 # Main application entry point
├── utils.cpp               # Utility functions
├── utils.h                 # Utility headers
├── xmlReader.cpp           # XML configuration reader
├── xmlReader.h             # XML reader headers
├── config.xml              # Configuration file
├── include/                # NatNet SDK headers
│   ├── NatNetCAPI.h
│   ├── NatNetClient.h
│   └── NatNetTypes.h
├── lib/                    # NatNet SDK libraries
│   ├── NatNetLib.dll
│   └── NatNetLib.lib
├── tinyxml2/               # TinyXML2 library
│   ├── tinyxml2.cpp
│   └── tinyxml2.h
├── CMakeLists.txt          # Build configuration
└── README.md               # This file

Building the Project

Prerequisites

1. Build the following libraries from source:
   • VTK - Follow VTK build instructions
   • OpenIGTLink - Build from OpenIGTLink repository
   • OpenIGTLinkIO - Build from OpenIGTLinkIO repository

Usage

Setup

1. Start Motive: Ensure OptiTrack Motive is running and streaming data
2. Configure Network: Make sure both applications are on the same network
3. Run Application: Execute the built executable

Configuration File

Edit config.xml to configure tools and network settings. The application will automatically use the rigid body names from Motive that match the configured tool names.

Runtime Controls

• Press 'q' or 'Q': Quit the application
• Console Output: Shows connection status and frame rate statistics

Data Flow

1. NatNet Client receives rigid body data from Motive
2. Data Handler processes each frame of motion capture data
3. Transform Conversion converts quaternion/position to 4x4 matrix
4. OpenIGTLink Server streams transforms to connected clients
5. Frame Rate Monitoring displays performance statistics

Integration with 3D Slicer

1. Install OpenIGTLink Extension in 3D Slicer
2. Create IGTLink Connector in Slicer
3. Set Connection: localhost:18944