Rigidbody2D.AddTorque

Parameters

Description

Apply a torque at the rigidbody's centre of mass.

Applying torque to the Rigidbody2D changes the Rigidbody2D.angularVelocity only. This change is scaled (divided) by the rotational Rigidbody2D.inertia. Therefore, a larger Rigidbody2D.inertia results in smaller changes to Rigidbody2D.angularVelocity, and a smaller Rigidbody2D.inertia results in larger changes to Rigidbody2D.angularVelocity.

When applying torque either as a force or an impulse, you can use any value to get the required change in Rigidbody2D.angularVelocity. However, if you require a specific change in degrees, then you must first convert the torque value into radians by multiplying with Mathf.Deg2Rad then multiplying by the Rigidbody2D.inertia.

The following example demonstrates this as an impulse:

Additional resources: Rigidbody2D.AddForce, Rigidbody2D.AddForceAtPosition

using UnityEngine;

public class TorqueRotationExample : MonoBehaviour
{
    // Add an impulse which produces a change in angular velocity (specified in degrees).
    public void AddTorqueImpulse(float angularChangeInDegrees)
    {
        var body = GetComponent<Rigidbody2D>();
        var impulse = (angularChangeInDegrees * Mathf.Deg2Rad) * body.inertia;

        body.AddTorque(impulse, ForceMode2D.Impulse);
    }
}