Module Script Blocks: Create Variables for Rooms
Variables for rooms are created as normal global variables in the Script Blocks module:

These variables must be of type Number and you usually want to have an associated time series.
If you later want to have information about how many people entered a room via certain entrances/exits and when, you can also create variables for individual cameras (if necessary even summed up for several cameras) (also variables of the Number type with the associated time series).