Building your first model

The fastest way to learn is to make a small model yourself. Click + New model in the library. You get an empty world.

1. Add an agent type

Open the Code tab. Under Agent types click + Agent type. Rename it to creature in the inspector.

2. Give it a property

Under creature, click + Property. Call it energy and set default to 50. This expression runs once for each agent at setup. Any DSL expression works there.

3. Add a setup rule

Under Setup rules click + Rule. The new rule's body is empty. Put this in it:

create_agents('creature', 30)

Now click Setup. Thirty agents appear, scattered randomly.

4. Add a rule for each tick

Under creature → Rules click + Rule. Body:

turn(random(-20, 20))
move_forward(1)
energy = energy - 1

This is a classic random walk that uses up energy. Click Setup, then Go. Your creatures wander around.

5. Add a die-off rule

Under creature → Rules, add another rule:

when:  energy <= 0
do:    die()

That's the whole loop: agents wander, lose energy and in the end die. Next you could plot the population over time, add food patches, or let creatures reproduce. Take it where you like.