Prey Behavior through Influence Maps Alicia Yeargin CS380, Fall 2011.

Prey BehaviorPrey Behaviorthroughthrough

Influence Influence MapsMaps

Alicia YearginAlicia Yeargin

CS380, Fall 2011CS380, Fall 2011

The IdeaThe Idea

How the idea came together… Big Cat Diary + Old, Useless Prototype = Idea.

Behavior of Prey Behavior of Prey AnimalsAnimals

What does a herd of prey do?

Behavior of Prey Behavior of Prey AnimalsAnimals

What does a herd of prey do? (According to Video Games) Research into the subject showed that animal

AI more often than not consisted of random wandering behaviors.

Hey, where ya’ going?Hey, where ya’ going?

I dunno, lol.I dunno, lol.

Behavior of Prey Behavior of Prey AnimalsAnimals

What does a herd of prey do? (Really.)

CreditCredit: : Wildebeest herd, Flicker, Wildebeest herd, Flicker, h_savillh_savillhttp://www.flickr.com/photos/h_savill/209372013/http://www.flickr.com/photos/h_savill/209372013/

Behavior of Prey Behavior of Prey AnimalsAnimals

What does a herd of prey do? (Step 1)

Migrate in a direction.

Behavior of Prey Behavior of Prey AnimalsAnimals

What does a herd of prey do? (Step 2)

SOME migrate in a direction. SOME eat.

Behavior of Prey Behavior of Prey AnimalsAnimals

What does a herd of prey do? (Step 3)

SOME migrate in a direction. SOME eat. SOME face different directions.

Behavior of Prey Behavior of Prey AnimalsAnimals

What does a herd of prey do? (Step 4)

Run when there’s a predator.

Influence MapInfluence Map

What it is (in my implementation)…

The blue represents attracting forces (negative values). The red represents repulsing forces (positive values).

2D grid of values, ranging from -2.0 to 2.0.

Influence MapInfluence Map

What I do (in my implementation)…

Simply have x, y for position and x, y for direction. They start in a random direction and read from the map.

An array of particles serve as the representation for prey.

Influence MapInfluence Map

What this does (in my implementation)…

Individual points move uniquely from one another. Each point’s path across the map is different each time.

Creates “guided” randomness. (Unpredictable + Logical)

Influence MapInfluence Map

How I used this (in my implementation)…

Used wall of blue to mimic migration. Used special green squares to mimic stopping

and eating.

Used walls of red to mimic herding.

Influence MapInfluence Map

A special case (in my implementation)…

A special predator mode can simulate predator presence. Added in a trail of repulsing red squares to mouse.

The map can be changed in real time to alter behavior.

Why it matters…Why it matters…

You may have the best-looking environments…

Why it matters…Why it matters…

…but you need something to make it feel ALIVE…

Why it matters…Why it matters…

…and something else to make it BELIEVABLE.

End.End.

Demo...Demo...