Rigidbody2D.AddTorque

Parameters

Description

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

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

When applying torque either as a force or an impulse, you can use any value to get the required change in 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 inertia.

The following example demonstrates this as an impulse:

Additional resources: AddForce, 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);
    }
}