Step 1 - Load a Theia C3D file

Before you begin, ensure you have unzipped the ProCalc Tutorials data as described in About the data in this tutorial.

For this tutorial, the example trial data (Walk01.c3d) was generated by using Nexus pipelines that merged the rotation data from Theia with existing Vicon data (only force plates in this instance). You can also use a C3D that was directly processed in Theia.

For information on how a Theia3D file is added to a Nexus session folder and how to merge Theia3D data with a Nexus trial, see Run Theia processing on video files in the Vicon Nexus User Guide.

When you open the file in ProCalc, skeletal data from Theia3D is visualized as a skeleton in the ProCalc 3D workspace:

Each Theia segment is visualized as a bone. Each bone has an axis system that shows the XYZ axes of the bone's local coordinate system, with the axis system placed at the segment's point of origin. 

The axis system is displayed as follows:

• X-axis: red
• Y-axis: green
• Z-axis: blue

Each segment that is read from the C3D file is interpreted as a ProCalc segment – that is, an entity with a position (the segment's origin) and an orientation in 3D space.

ProCalc now lets you define your own calculations based on the segments.