Problem with car physics

Hi.
I created a car with physics, but my car is moving to the left, I don't press any key, the problem is the centerOfMass, if I delete the centerOfMass, the movement of the car is correct (but without central mass). The code is:

Code (csharp):

1.  
2. using UnityEngine;
3. using System.Collections;
4.  
5. public class LogicCar : MonoBehaviour {
6.     //Variables
7.     private float Velocity = 20.0f;
8.     private float Rotation = 15.0f;
9.     private int forceBrake = 70;
10.  
11.     //Wheels
12.     public WheelCollider WheelBackL;
13.     public WheelCollider WheelBackR;
14.     public WheelCollider WheelFrontL;
15.     public WheelCollider WheelFrontR;
16.  
17.     void Start()
18.     {
19.         this.rigidbody.centerOfMass = new Vector3(0, 0, 0);
20.     }
21.  
22.     // Update
23.     void FixedUpdate () {
24.         //Move forward and backward
25.         WheelBackL.motorTorque = -Velocity * Input.GetAxis("Vertical");
26.         WheelBackR.motorTorque = -Velocity * Input.GetAxis("Vertical");
27.         //Turn left and right
28.         WheelFrontL.steerAngle = Rotation * Input.GetAxis("Horizontal");
29.         WheelFrontR.steerAngle = Rotation * Input.GetAxis("Horizontal");
30.         //Brake
31.         if (Input.GetKey("space"))
32.         {
33.             WheelBackL.brakeTorque = forceBrake;
34.             WheelBackR.brakeTorque = forceBrake;
35.         }
36.         else
37.         {
38.             WheelBackL.brakeTorque = 6;
39.             WheelBackR.brakeTorque = 6;
40.         }
41.         //Automatic reset direction
42.         if (!Input.GetKey("a")  !Input.GetKey("d"))
43.         {
44.             WheelFrontL.steerAngle = 0;
45.             WheelFrontR.steerAngle = 0;
46.         }
47.     }
48. }
49.  
50.  

Does anyone know why?
Thanks

 

Well if you are changing the center of mass, of course its going to effect your car. You set it at 0,0,0 which is probably wrong, the physics engine will calculate the COM automatically. The usual thing to do is lower the Center Of Mass.

Code (csharp):

1. public Vector3 comOffset = new Vector3(0,-1,0);
2.  
3.  
4. Vector3 com = rigidbody.centerOfMass;
5. com -= comOffset;
6. rigidbody.centerOfMass = com;

 

The problem continue. This time I created a empty object and I have added the mass in this object, but nothing.

Code (csharp):

1.  
2. public Transform Rwheels;
3.  
4.     void Start()
5.     {
6.         this.rigidbody.centerOfMass = Rwheels.localPosition;
7.     }

 

Heya Darksoul,

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It would be great to have you on board. No need to make a payment yet, just make a pledge min: $50 to guarantee your stake in the final project.

Cheers


Jeff