A Desire Plot is a data object which enables you to set up the conditions needed to visually track the preferred travel choices and routes of specified Entities. A Desire Plot enables you to filter for a specific Entity Type (or Entities) give it (or them) a unique colour, and track their journey through your simulation, with its colour-coded, tracked trail displayed in the LEGION Simulator workplace within an associated Desire Line Diagram. This 'visual journey' of Entities' most desired routes is known as a 'Desire Line Diagram'.

You can set up several Desire Plots but each plot must correspond to a particular route through a model and it must be associated with a single user-defined colour for each Entity captured by the Desire Plot's filter settings. The aim is to reveal preferred routes through a model, which can help in focusing attention on the most crucial, or most utilised, areas of a model.

You can associate a Desire Plot with several origin and destination objects (to indicate possible routes) and then set its filter to pick up Entities of interest. Once you have set up the required Desire Plots, you can activate Desire Line Diagrams by selecting Analysis > Start Desire Line Diagram Generation or clicking the icon. Desire-line diagrams use the Entity colour scheme specified in desire plots and they display only the trails of Entities, not the Entities themselves. To record the output of desire-line diagrams, you can set up a Screen Camera track on the Timeline, and add Snapshot events.