This information is for Vicon Evoke 1.6. For up-to-date help, see the latest Evoke documentation.

Vicon Evoke banner

The following topics provide information about some of the fundamental features that underpin the way Evoke works.


Device synchronization session

When you connect Evoke to a live system of cameras and/or Vicon connectivity devices, a new device synchronization session is created. To identify the current device synchronization session, look in the timebar at the bottom of the Workspace for the value in brackets [ ]. 

When you first open Evoke, the device synchronization session starts at 1 and the Frame and Seconds that are displayed are relative to the start of that session. 

The device synchronization session enables the system to synchronize all devices. A new system session starts when:

  • The hardware is rebooted.
  • A device is added to the system.
  • The frame rate changes.

Live review

When Evoke is live, the pause buffer is a feature that enables data to be stored to memory for live review (see Review live data in the Vicon Evoke User Guide). The maximum amount of data that can be stored is controlled by the Pause Buffer Size, which you can configure in the Output section of the Processing panel (see Processing parameters). The Pause Buffer Size specifies the duration of the pause buffer, and thus the amount of data that is always accessible.

The data types stored in the pause buffer are identical to the data types that are saved when capturing data. This includes data such as centroids in each camera view, object pose, and system performance metrics such as latency. For more information on the data types that are stored in a capture, see Capture live data in the Vicon Evoke User Guide.

The pause buffer influences the behavior and workflow of multiple aspects of the software including:

  • Object creation and manipulation
  • Reviewing recent live data
  • Graph Plots

Auto save

With Evoke started, its default behavior is to save all settings automatically according to the Auto-save interval setting (see Preferences parameters).

All auto-saved files except preferences and subject view preset files are located in this folder:


Preferences and subject view preset files are located in the following folder so that you can use them in later (or earlier) versions of Evoke:


Auto-save files are only updated if there have been changes since the last auto-save.

As you work within Evoke, files populate into the above folder according to the temporary filenames listed in the following table. When you close Evoke properly, the temporary filenames are converted and saved as normal filenames.

Temporary filenameNormal filename

If Evoke terminates abnormally (including closing the process in Task Manager), the temporary filename does not convert to its normal filename and is left present in the LastRun folder. 

When you re-launch Evoke, if any of the auto-save files are detected, you are prompted to confirm which files you want to load:

  • To load the most recent (auto-saved) settings, click Yes.
  • To load settings from the last successfully closed session, click No.

This feature prevents you from losing your settings if Evoke closes abnormally, for example, due to process termination, machine reboot, etc.

To control the auto-save settings:

  • From the Settings menu, select Preferences (or press Shift+P) and in User Preferences, go to the General section.
    • To disable auto-save, clear Enable auto-save. The default is selected.
    • To change the auto-save interval, enter a value (in seconds) for the Auto-save interval. The default is 60 seconds.

If you have system settings that you are likely to re-use, we recommend saving them by clicking System Settings at the top right of the Evoke toolbar, selecting Manage and then clicking the Save button, rather than relying on the auto-save feature.