Add Gravitational Attraction to RigidBody2D?

Questions & Answers
1

I want to make a platformer with the style of Angry Birds Space’s great outerspace physics. To do this, I need to make a planet sprite have a gravitational force. To do this, I added a CircleCollider2D, which has a RigidBody2D I can alter. How can I add gravitational attraction to this object’s RigidBody2D? C# code examples would be appeciated.

2

for simple simulation try this

public GameObject planet; // assign your planet GO in unity editor here
public float gravityFactor = 1f; // then tune this value  in editor too

void FixedUpdate(){
rigidbody.AddForce((planet.transform.position - transform.position).normalized * rigidbody.mass * gravityFactor / (planet.transform.position - transform.position).sqrMagnitude);
}
3

You need to calculate the direction components, normalize them and then add a force to that vector, whose strength is defined by the inverse-square law:

var intensity = 5.5f;
components = transform.position.planet - transform.position.ship;
comp_normalized = components / components.magnitude;
force = comp_normalized * (intensity * (1 / Vector2.Distance(from, end)))
rigidbody2D.addForce(force);

Play around with intensity, to suit your needs. (I don’t know C#, sorry.)

4

Something like a central force? Something like this maybe, but I´m not sure what you mean:

Transform worldCenter;
private readonly static float gravity = 0.1f; 

void Update(){
    AddGravitationalForce();
}

void AddGravitationalForce(){
    Vector3 force = (transform.position - worldCenter.position)
    force = force.normalized/force.sqrMagnitude;
    force *= gravity*Time.deltaTime;
    rigidbody2D.AddForce(new Vector2(force.x, force.y));
}