Faux Gravity

Questions & Answers
1

I followed Brackey’s tutorial and it has been very helpful, however I have a problem. For the items to be affected by gravity, they also act on others. I would like to have objects that are affected by gravity but don’t attract other objects.

This is the code I’m using:

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

public class GravityAttractor : MonoBehaviour

{
public static List Attractors;

public Rigidbody2D rb;

const float G = 66.74f;

void Awake()
{
    rb = GetComponent<Rigidbody2D>();
}
void FixedUpdate()
{
    foreach (GravityAttractor attractor in Attractors)
    {
        if (attractor != this)
        {
            Attract(attractor);

        }
    }
}

void OnEnable()
{
        if (Attractors == null)
        Attractors = new List<GravityAttractor>();
        Attractors.Add(this);

}

void OnDisable()
{
        Attractors.Remove(this);
   
}

public void Attract(GravityAttractor objToAttract)
{
    Rigidbody2D rbToAttract = objToAttract.rb;

    Vector2 direction = rb.position - rbToAttract.position;
    float distance = direction.magnitude;

    if (distance == 0f)
        return;

    float forceMagnitude = G * (rb.mass * rbToAttract.mass) / Mathf.Pow(distance, 2);
    Vector2 force = direction.normalized * forceMagnitude;

    rbToAttract.AddForce(force);
}

}

2

Just have a public bool which you can set from the inspector which says whether to run the Attract function or not:

using System.Collections;

using System.Collections.Generic;

using UnityEngine;

public class GravityAttractor : MonoBehaviour

{ public static List Attractors;

 public Rigidbody2D rb;
public bool attractsOthers = true;
 const float G = 66.74f;
 void Awake()
 {
     rb = GetComponent<Rigidbody2D>();
 }
 void FixedUpdate()
 {
if (attractsOthers)
{
     foreach (GravityAttractor attractor in Attractors)
     {
         if (attractor != this)
         {
             Attract(attractor);
         }
     }
}
 }
 void OnEnable()
 {
         if (Attractors == null)
         Attractors = new List<GravityAttractor>();
         Attractors.Add(this);
 }
 void OnDisable()
 {
         Attractors.Remove(this);
    
 }
 public void Attract(GravityAttractor objToAttract)
 {
     Rigidbody2D rbToAttract = objToAttract.rb;
     Vector2 direction = rb.position - rbToAttract.position;
     float distance = direction.magnitude;
     if (distance == 0f)
         return;
     float forceMagnitude = G * (rb.mass * rbToAttract.mass) / Mathf.Pow(distance, 2);
     Vector2 force = direction.normalized * forceMagnitude;
     rbToAttract.AddForce(force);
 }
}