NPC Personality Vector Example

This repository contains a simplified example implementation of a personality component for non-player characters in simulation games. I made it to track how likely characters are to engage in different behaviors. Also, I wanted to be able to calculate how compatible two personalities are.

The Personality class represents character personalities as a vector of real-valued numbers. You can access each personality trait using a corresponding enum value. Also, you can calculate the similarity of two personalities on a scale from -1 to 1. -1 means they are diametrically opposed, and 1 means they are completely compatible.

By default, all personality attributes are clamped on the interval [-100, 100]. Setting the value of ATTRS_MAX_ABS will adjust this interval. For instance, Personality<PersonalityAttrs>.ATTR_MAX_ABS = 50 will change the interval to [-50, 50]. ATTRS_MAX_ABS may only be a positive number.

This package can be used with Unity. You will need to write your own PersonalityController class to wrap the personality instance and make it available within the Inspector. See the example below.

If you have any questions, create a new GitHub issue. Don't forget to star the repository if you find this useful.

Package Dependencies

• MathNet.Numerics v5.0.0

General C# Example

using PersonalitySample;

// Start by defining an enum stating what the attributes of a relationship are.
public enum PersonalityAttrs
{
    VALUES_MONEY,
    VALUES_FAMILY,
    VALUES_LOYALTY,
    VALUES_POWER,
    VALUES_LOVE
}

Personality<PersonalityAttrs> personalityA = new Personality<PersonalityAttrs>();
personalityA.Set( PersonalityAttrs.VALUES_MONEY, 45 );
// Output: Personality(VALUES_MONEY=45, VALUES_FAMILY=0, VALUES_LOYALTY=0, VALUES_POWER=0, VALUES_LOVE=0)

Personality<PersonalityAttrs> personalityB = new Personality<PersonalityAttrs>();
personalityB.Set( PersonalityAttrs.VALUES_MONEY, -10 );
// Output: Personality(VALUES_MONEY=-10, VALUES_FAMILY=0, VALUES_LOYALTY=0, VALUES_POWER=0, VALUES_LOVE=0)

Console.WriteLine(personalityA.Similarity(personalityB));
// Output: -0.3
// These characters are not very compatible.

personalityB.Set( PersonalityAttrs.VALUES_MONEY, 45 );
Console.WriteLine(personalityA.Similarity(personalityB));
// Output: 1
// These characters are now 100% compatible

Unity Example

using UnityEngine;
using PersonalitySample;

public class PersonalityController : MonoBehaviour
{
    public enum PersonalityAttrs
    {
        VALUES_MONEY,
        VALUES_FAMILY,
        VALUES_LOYALTY,
        VALUES_POWER,
        VALUES_LOVE
    }

    public Personality<PersonalityAttrs> personality;

    // Initial values for personality traits
    public float values_money;
    public float values_family;
    public float values_loyalty;
    public float values_power;
    public float values_love;

    void Awake()
    {
        personality = new Personality<PersonalityAttrs>();
        personality[VALUES_MONEY] = values_money;
        personality[VALUES_FAMILY] = values_family;
        personality[VALUES_LOYALTY] = values_loyalty;
        personality[VALUES_POWER] = values_power;
        personality[VALUES_LOVE] = values_love;
    }
}