====== Creating a Virtual Laboratory ======

A Virtual Laboratory is not a physical segment in Visual3D but is equivalent to a physical segment to the effect that it has a **Segment Coordinate System** that can be used to represent the laboratory (or other objects) and has an associated **surface model** that can be animated as part of the scene. A typical use of the Virtual Laboratory is to represent the floor so that motion capture markers can be projected onto the floor. This can be used for creating [[Visual3D:Documentation:Pipeline:Model_Based_Data_Commands:Joint_Angle#Joint_Angle_Normalization|Normalized Joint Angles]].

For more information please view the [[Visual3D:Tutorials:Modeling:Virtual_Laboratory_|Virtual Lab Tutorial]].

=== Create Landmarks ===

To create the Virtual Lab segment first create 4 Landmarks: **LAB_Origin**, **LAB_X**, **LAB_Y**, and **LAB_Z**.

To create **Lab_Origin** landmark, enter the following into the landmark Tab:

Landmark Name=**Lab_Origin**
Starting Point= leave blank
Existing Segment= **LAB**
Offset Using the Following ML/AP/AXIAL Offset ML=**0** , AP=**0** , AXIAL=**0**
Calibration Only Landmark=**Leave Unchecked**
To create **Lab_X** landmark, enter the following into the landmark Tab:

Landmark Name=**Lab_X**
Starting Point=leave blank
Existing Segment=**LAB**
Offset Using the Following ML/AP/AXIAL Offset ML=**0.1** , AP=**0** , AXIAL=**0**
Calibration Only Landmark=**Leave Unchecked**
To create **Lab_Y** landmark, enter the following into the landmark Tab:

Landmark Name=**Lab_Y**
Starting Point=leave blank
Existing Segment=**LAB**
Offset Using the Following ML/AP/AXIAL Offset ML=**0** , AP=**0.1** , AXIAL=**0**
Calibration Only Landmark=**Leave Unchecked**
To create **Lab_Z** landmark, enter the following into the landmark Tab:

Landmark Name=**Lab_Z**
Starting Point=leave blank
Existing Segment=**LAB**
Offset Using the Following ML/AP/AXIAL Offset ML=**0** , AP=**0** , AXIAL=**0.1**
Calibration Only Landmark=**Leave Unchecked**
=== Create Segment ===

A subset of 3 of these Landmarks can be used to represent the Segment Coordinate System.

To create the segment, switch to the Segment Tab in model builder mode.

In the Segment Name combo box type **Virtual Lab**
Check the **Kinematic Only** Check Box
Click the **Create** button
In the segment definition dialog, enter the following:

Define Proximal Joint and Radius\\

Lateral= Joint=**Lab_Z** Medial= Radius=**0.001**
Define Distal Joint and Radius\\

Lateral= Joint= **Lab_Origin** Medial= Radius=**0.001**
Extra Target To Define Orientation (if needed)\\

Location **Lateral**=**Lab_X**\\

Select Tracking Markers**\\
**
**Use Calibration Targets for Tracking Checked**
Select **Build Model**

=== Add a surface model ===

To add a surface model select the **Virtual Lab** Segment and switch to the **Segment Properties** Tab. Near the bottom of the dialog, Browse for a Model File and select **Apply** after the selection.