Basic Node Based Pathfinding

Unity Engine
1

Hi everyone,

I am new to pathfinding but i have read and watched through some articles, blogs and videos about Pathfinding.

Since those that i have read and watched from are mainly for RTS Games, Grid Based Pathfinding.

I couldnt find any tutorials where it explains in details of how you can make your own Node Based Pathfinding System.

So i hope, you guys could give me some insightful information to enlight me or even provide useful links which can help me.

I just want to make a very Basic Node Based Pathfinding system, and from that i hope to work from it to make it into a Pathfinding System suitable for my game.

Thank you in advance, you help is very much appreciated.

2

Its easy enough to use Unity`s built in NavMesh. so:

  1. bake your nav mesh
  2. create a gameObject and call it “Waypoint” or whatever (adding a gizmo to it is useful). Place them at intervals, creating a path you want you NPC to follow
  3. add this script to your NPC and then drag all your waypoints into the waypoint list in the inspector
using UnityEngine;
using System.Collections;
public class PatrolTest : MonoBehaviour
{
    private enum PatrolBehaviorState { MovingToNextPatrolPoint = 0 }
    public Transform[] patrolPoints; //list of patrol points assigned to this gameobject
    private PatrolBehaviorState patrolBehaviorState;
    private int patrolPointIndex;

    private bool enable = true;
    private NavMeshAgent nav; //reference to the Nav mesh agent attached to this object
    private Animator anim; //reference to the Animator attached to this object
    private bool stopped;


  public void Start()
  {
    anim = GetComponent<Animator>();
    nav = GetComponent<NavMeshAgent>();
    anim.SetFloat("Speed", 1f);
    patrolPointIndex = 0; //set patrol points index to the first point
    patrolBehaviorState = PatrolBehaviorState.MovingToNextPatrolPoint;
  }

  Vector3 GetCurrentDestination()
  {
      return patrolPoints[patrolPointIndex].position; //returns the current destination
  }

  void ChooseNextDestination() //chooses the next patrol point
  {
      patrolPointIndex++;
      if (patrolPointIndex >= patrolPoints.GetLength(0)) //if we reached the last patrol point then go back to the first
     {
        patrolPointIndex = 0;
     }
   }

  void UpdateMovingToNextPatrolPoint()
  {
       if ((GetCurrentDestination() - transform.position).magnitude < 1.5f) //check if we are close to the current assigned point
       {
           ChooseNextDestination(); //choose the next point to go to
          var newRotation = Quaternion.LookRotation(GetCurrentDestination() -    transform.position).eulerAngles;
          newRotation.x = 0;
          newRotation.z = 0;
          transform.rotation = Quaternion.Slerp(transform.rotation, Quaternion.Euler(newRotation), Time.deltaTime);
        }
       nav.SetDestination(GetCurrentDestination()); //set the Nav mesh agent on a path to the     current destination
  }

  void Update()
  {
       if (patrolBehaviorState == PatrolBehaviorState.MovingToNextPatrolPoint)
       {
           UpdateMovingToNextPatrolPoint();
       }
   }
}
3

Almost certaintly all you have read about Grid Based Pathfinding can be extrapolated to Node Based Pathfinding. Each cell in a grid can be thought as a node.
One of the most standard algorithms is A* (A star), and is not so difficult to implement on your own if you are interested.

4

4:) Add navmeshagent to your NPC.

5

I dont want to use the Unity Based Navigation Mesh.
I want to code my own.
How may i do that ?