Lecture IX The savannah game 1 The savannah as a bigraph ( thanks - PowerPoint PPT Presentation

Lecture IX The savannah game 1

The savannah as a bigraph ( thanks to Benson et al. ) F locale 0 2 1 next 3 5 4 Nodes with control locale are locales ; their contiguity is repre- sented by linkage of next nodes. 2

F locale 0 2 1 next 3 5 4 F ◦ G G 0 1 2 deer lion 3 4 5 3

Reaction rules for animals lion lion deer deer An animal moves to a neighbouring region lionalert lionpaired lion lionalert deerseen deerheld deer deerseen lionpaired lion A lion becomes alert to a nearby deer An alerted lion pairs with another nearby 4

More reaction rules for animals lionalert lionpaired lion deerseen deerheld lionpaired An alerted lion can attract its pair from a neighbouring locale lionpaired lion lion lionpaired deerheld Paired lions can kill their deer 5

The savannah game • Children roam a featureless field; • each child has a GPS on her back, and carries a laptop . • On the laptop is a game server ... • ... which knows each child’s location from her GPS. • The game server pretends that the field is a savannah ... • ... and allows the children to “be” virtual lions ... • ... and to “kill” virtual deer on their laptops. 6

The field and the virtual savannah [ xy ] 0 1 2 next 4 3 5 Open field to be occupied by Virtual savannah with six children with GPS+laptop locales and grid spots 7

Reaction rules for virtual animals a ′ a ′ a a a a [ xy ] [ xy ] [ x ′ y ′ ] [ xy ] [ x ′ y ′ ] [ xy ] b field b child lion lion lion ( | x − x ′ | + | y − y ′ | = 1 ) A child/lion enters the game at spot [ xy ] A virtual lion moves to another spot (similarly for a deer) (similarly for a deer) a a b b lionalert lion child childalert deerseen deer A child/lion becomes alert to a deer in its locale c ( child c � ( lion ac | deer b )) c ( childalert c � ( lionalert ac | deerseen bc )) / / ◮ 8

More reaction rules for virtual animals a ′ a ′ a a lionalert lionpaired lion lionpaired b b child childpaired childalert childpaired deerseen deerheld An alerted child/lion can pair with another in its locale a ′ a ′ a a lionpaired lion lionpaired lion b childpaired child childpaired child deerheld The pair of child/lions kill the deer 9

What does the savannah game illustrate? • The interplay between placing and linking • Modelling physical and virtual at once • How to combine topographical and metrical space • The interplay between a human and a complex artifact 10

What does the savannah game illustrate? • The interplay between placing and linking • Modelling physical and virtual at once • How to combine topographical and metrical space • The interplay between a human and a complex artifact 10-a

What does the savannah game illustrate? • The interplay between placing and linking • Modelling physical and virtual at once • How to combine topographical and metrical space • The interplay between a human and a complex artifact 10-b

What does the savannah game illustrate? • The interplay between placing and linking • Modelling physical and virtual at once • How to combine topographical and metrical space • The interplay between a human and a complex artifact 11