# Unitysteer - Rigidbody with gravity stops steering

When I have rigidbody with gravity enabled on the object being steered. after about a moment of movement, it comes to a stop. I disable gravity, and it works fine. If I change the mass in rigidbody, it goes further. Is there any way to remove mass from the movement calculation?

The reason why it stops is because of friction with the ground. The object looses energy due to that friction and slows down until it comes to a complete stop. Reducing the mass will only delay the stop time. What I ll suggest is to

1) add a force to the object and change it based on the rigid body's velocity

So you could try something like this:

(This is in C#)

float maxVelocity = 10f; float myForceSize = 0f public float variator = 0.1; public Vector3 initVel = Vector3.forward * 10f; // Set the initial velocity of the object

funtion Start(){ rigidbody.velocity = initVel; }

function FixedUpdate () { if (maxVelocity < rigidbody.velocity.magnitude ) // When speed is too fast myForceSize -= variator; else if (maxVelocity > rigidbody.velocity.magnitude) // When speed is too slow myForceSize += variator; else // When speed is just nice myForceSize = 0f;

`````` rigidbody.AddForce (Vector3.up * myForceSize);

``````

}

2) Directly change to velocity per fixed update (Not recommended tough)

rigidbody.velocity = myVel; // Where myVel is a Vector3

3) You can try moving the object via Translation : myBody.transform.Translate(Vector3.forward * mySpeed);

Hello Jon,

As denewbie points out, if the character has a rigidbody, then AutonomousVehicle's behavior will be affected by physics.

You have several options:

1. Reduce the rigidbody's mass.
2. Increase the force being applied to the object.
3. Alter AutonomousVehicle.ApplySteeringForce and not take Mass into account.

You could even create a simpler vehicle if the considerations taken by AutonomousVehicle are too elaborate for the effect you're trying to achieve.