Constraint an object speed

Question

Hello,

I don't want my ball goes at a greater speed as I set in "AddForce()".

Is this code correct ?

     void Update()
     {
         if (ball.GetComponent<Rigidbody>().velocity.magnitude > 250.0f)
         {
             ball.GetComponent<Rigidbody>().SetMaxAngularVelocity(250.0f);
         }
     }

Answer 1

Best Answer

Answer by LK84 · Jan 11, 2017 at 09:39 AM

SetMaxAngularVelocity only constraints the rotational velocity. I assume you want to constraint the translational velocity since you state this in your if-condition? And: Put in in the FixedUpdate() loop!

To constrain the translational velocity you got two options:

The non-physics way (I don't recommend because you gonna mess with the physics engine)
The physics way which probably takes a little more time to get exactly what you want

For (1) You could write something like this:

   const float maxSpeed=250;  
   void Start()
     {
     rigidbody=GetComponent<Rigidbody>();
     }
     void FixedUpdate()
     {
                  if(rigidbody.velocity.magnitude > maxSpeed)
                  {
                         rigidbody.velocity = rigidbody.velocity.normalized * maxSpeed;
                  }
     }

For (2) you can either experiment with the drag value of your rigidbody in the inspector or write your own function, something like this:

 rigidbody.AddForce(-rigidbody.velocity*dampC); //dampfC is a damping Coefficient you can define yourself

Add comment · Show 2 · Share

Gvrv · Jan 11, 2017 at 09:51 AM 0

Share

Thanks !

I tried the first way, it works like a charm :)

LK84 Gvrv · Jan 11, 2017 at 09:53 AM 0

Share

ok, but be careful using it. It's not the "physical correct way" to do it.

Answer 2

Answer by tanoshimi · Jan 11, 2017 at 09:37 AM

You're muddling up velocity (position) with angularVelocity (rotation). Also you don't need to keep setting a maximum value every frame - you can just set it once and it will persist. You should also try to avoid using GetComponent in Update - it's expensive. Find the rigidbody once in Start and re-use the result from them on.

Try this instead:

 private Rigidbody rb;

 void Start() {
   rb = ball.GetComponent<Rigidbody>();
 }

 void Update()
  {
      if (rb.velocity.magnitude > 250.0f)
      {
          rb.velocity = rb.velocity.normalized * 250f;
      }
  }

Add comment · Share

Constraint an object speed

2 Replies

Your answer

Follow this Question

Related Questions