Using conditions is a powerful method for modelling situations where certain pre-defined criteria may prompt operational interventions or cause pedestrians to make certain kinds of decisions.

Such criteria might include things like a combination of occupancy, density, speed or other pedestrian experience metrics. For example, you may wish to model opening a new exit route when a certain level of density is reached for Entities travelling towards a particular Final Destination. If you are using Environment Maps based on FDS output files, you can also create conditions relating to temperature, visibility and toxicity.

In LEGION Model Builder, the Spatial Objects that can make use of Conditions to influence the movement of Entities are: Direction Modifiers, Focal Nodes, Queues, Queue Groups, Exits and Delay Points.

In order for these objects to have any conditions to use, you must first place Analysis Objects (Zones, Lines or Poly-lines) in your model and set up Analyses. Conditions can then be defined using the standard logical expressions (=, <, >, AND, OR, NOT).

To help you better understand Conditions, familiarise yourself with "About Analysis Objects", "Setting up analyses", and as detailed in in LEGION Simulator and Setting Direction Modifier Parameters .