Algorithm (Workflow)

This function, Vstray, is designed to return a list of all stray markers detected by a tracking system. It is part of the SG-Library and interacts with a global variable, vicra_global, which is expected to be initialized by the Vicra driver.

Input Parameters

The function does not take any input parameters directly when called. Instead, it relies on the global variable vicra_global to be properly initialized and configured.

Output Results

• L: A list of stray markers detected by the system.
• n: The number of stray markers detected.
• tcam: The timestamp indicating when the camera captured the tracker data, measured in camera-time seconds.
• tpc: The timestamp indicating when the PC requested the transformation data from the camera, measured in PC-time seconds.

Algorithm Steps

1. The function begins by checking if the global variable vicra_global is empty.
2. If vicra_global is empty, an error is thrown with the message: "Vicra driver not initialized. Please call VTReset first."
3. If vicra_global is initialized, the function proceeds to call the vstray method on vicra_global.
4. The vstray method returns four outputs: L, n, tcam, and tpc.
5. These outputs are then returned by the function to the caller.

Assumptions

• The global variable vicra_global must be properly initialized before calling this function.
• The function assumes that the vstray method of vicra_global is correctly implemented and returns the expected outputs.
• The timestamps tcam and tpc are measured in seconds but by different clocks, and they may have a non-constant offset due to clock drift.