VIPRA Behavior Tutorial

§ markers point to the Behavior Syntax Reference

Ex. Creating An Example Behavior

Here we will make a couple of example Behaviors.

Ex.1. The Simplest Behavior

This example is a simple Behavior that causes every pedestrian to stand still for the duration of the simulation.

Code

Types:           // Types Declarations (§T.) say what types of pedestrians there are
  person
.
 
Selector:        // Selectors (§S.) set how pedestrians are chosen to have the type
  Type: person
  Select: Everyone  // in this case everyone is selected
.
 
Action (person): // Actions (§A.) decide what pedestrians of the given type do
  Response: set velocity {0}  // in this case they are always stopped
.

Ex.2. An Announcment Event

This Behavior shows Events, with an announcement. In this example, we will make a simple Behavior and add to it.

Code

Types:                                // Types Declaration(§T.)
  Listener
.
 
Selector:                             // Selector (§S.)
  Type: Listener
  Select: Everyone
.
 
Event:                                // Event (§E.)
  Name: Announcement
  Start: 10 seconds after !Start      // Start Condition (§C.)
  End: 10 seconds after !Announcement // End Condition (§C.)
 
.
 
Action (Listener):                    // Action (§A.)
  Condition: !Announcement occurring  // Condition (§C.) sets what causes the pedestrian to do this action
  Response: set velocity {0}
. 

In this example, an announcement will start after 10 seconds and last for 10 seconds.

While the announcement is occurring, every pedestrian will be stopped to listen.

Ex.2.1. A bit more realistic

Everyone stopping to listen isn't very realistic, so we can change it slightly.

Code

Types:                                // Types Declaration(§T.)
  Listener
.
 
Selector:                             // Selector (§S.)
  Type: Listener
  Select: 10%
.
 
Event:                                // Event (§E.)
  Name: Announcement
  Start: 10 seconds after !Start      // Start Condition (§C.)
  End: 10 seconds after !Announcement // End Condition (§C.)
 
.
 
Action (Listener):                    // Action (§A.)
  Condition: !Announcement occurring  // Condition (§C.)
  Response: set velocity {0}
. 

In this example, only 10% of pedestrians will actually stop to listen to the announcement. (probably still an over-estimation)

Ex.2.2. Adding more

A black-and-white, either pedestrians stop to listen or don't, may not be as realistic as we would like.

Code

Types:                                // Types Declaration(§T.)
  Listener
  Partial_Listener
.
 
Selector:                             // Selector (§S.)
  Type: Listener
  Select: 10%
.
 
Selector:                             // Selector (§S.)
  Type: Parital_Listener
  Select: 25%
.
 
Event:                                // Event (§E.)
  Name: Announcement
  Start: 10 seconds after !Start      // Start Condition (§C.)
  End: 10 seconds after !Announcement // End Condition (§C.)
 
.
 
Action (Listener):                    // Action (§A.)
  Condition: !Announcement occurring  // Condition (§C.)
  Response: set velocity {0}
.
 
Action (Parital_Listener):            // Action (§A.)
  Condition: !Announcement occurring  // Condition (§C.)
  Response: scale velocity 0.75
.

In this 10% of pedestrians stop to listen, another 25% slow down to listen, and the rest behave normally.