The smelling function using a graph-based system

In this recipe, we take a mixed approach to tag vertices with a given odor particle that collides with it.

Getting ready

The vertices should have a broad collider attached so that they catch the odor particles nearby.

How to do it…

1. Add the following member variable to the odor-particle script to store its parent ID:

   public int parent;

2. Create the new odor-enabled class, deriving from the original vertex:

   using UnityEngine;
   using System.Collections;
   using System.Collections.Generic;
   
   public class VertexOdour : Vertex
   {
       private Dictionary<int, OdourParticle> odourDic;
   }

3. Initialize the odor dictionary in the proper function:

   public void Start()
   {
       odourDic = new Dictionary<int, OdourParticle>();
   }

4. Add the odor to the vertex's dictionary:

   public void OnCollisionEnter(Collision coll)
   {
       OdourOdourParticle op;
       op = coll.gameObject.GetComponent<OdourParticle>();
       if (op == null)
           return;
       int id = op.parent;
       odourDic...