.. _interaction-analysis:

********************************************************
Interaction Tracking
********************************************************

FindFace Multi can provide interaction tracking and analysis. To harness this functionality, you must enable :ref:`face clustering <clusters>`. 

When tracking interactions, the system automatically determines a circle of people with whom a person has previously been in contact. For each person from the first circle, the system builds another circle of connected people, and so on. Overall, interaction analysis is three-circles deep.

.. note::
   You can track interactions between bodies and vehicles as well. Access this functionality via :ref:`HTTP API <api>`. Note that body and vehicle clustering must be enabled beforehand.

The interaction analysis is available on the :guilabel:`Interaction Tracking` tab. 

|interaction_en|

.. |interaction_en| image:: /_static/interaction_en.png
   :scale: 80%

.. |interaction_ru| image:: /_static/interaction_ru.png
   :scale: 80%

.. tip::
   You can also display the circle of connected people right from the :guilabel:`Clusters` tab and :guilabel:`Record index` tab by clicking on the handshake icon.

   |interaction_clusters_handshake_en|

   .. |interaction_clusters_handshake_en| image:: /_static/interaction_clusters_handshake_en.png
      :scale: 60%

   .. |interaction_clusters_handshake_ru| image:: /_static/interaction_clusters_handshake_ru.png
      :scale: 60%


On the :guilabel:`Interaction Tracking` tab, click on a person to display their first circle of interactions and associated events. Keep on to unveil the entire tree of interactions.

|interaction_circles_en|

.. |interaction_circles_en| image:: /_static/interaction_circles_en.png
   :scale: 50%

.. |interaction_circles_ru| image:: /_static/interaction_circles_ru.png
   :scale: 50%


You can apply the available filters to the interaction tracking:

.. tip::
   For example, you can find older adults or people without a face mask who are directly or indirectly related to a potentially contagious person.

* :guilabel:`Matches`: display clusters only with/without matches, or all events.
* :guilabel:`Watch lists`: display clusters only for a selected watch list.
* :guilabel:`Camera groups`: display only clusters from a selected group of cameras.
* :guilabel:`Cameras`: display only clusters from a selected camera.
* :guilabel:`Record name`: display clusters with a given record name.
* :guilabel:`Date and time`: display only clusters formed within a certain period.
* :guilabel:`First cluster even`: display only the first cluster event within a certain period.
* :guilabel:`Cluster event`: display only cluster event within a certain period.
* :guilabel:`ID`: display a cluster with a given ID.

.. rubric:: Specific filters for face clusters

* :guilabel:`Age`: display clusters with people of a given age.
* :guilabel:`Beard`: filter clusters by the fact of having a beard.
* :guilabel:`Emotions`: display clusters with given emotions.
* :guilabel:`Gender`: display clusters with people of a given gender.
* :guilabel:`Glasses`: filter clusters by the fact of wearing glasses.
* :guilabel:`Liveness`: filter clusters by face liveness.
* :guilabel:`Face mask`: filter clusters by the fact of wearing a face mask.

When searching through a circle of interactions, apply the following additional settings:

* :guilabel:`Interaction search based on the episode last event`: check to analyze contacts between individuals using the last event of an episode. In this case, having found truly associated people is most probable as they simultaneously leave a camera’s field of view. If the option is disabled, the system will use the best event of an episode for interaction search.
* :guilabel:`Maximum gap between the appearance of individuals to consider them connected, seconds`: maximum time in seconds between the appearance of individuals to consider them related.