How to determine speed of an object when using transform.position

Question

Hi, I am using the following code to rotate and move the player

         float cameraSmooth = 5.0f;
         float modX;
         float modZ;
         float moveSpeed = 50.0f;
         
         modX = Input.GetAxis("Horizontal") * Time.deltaTime * moveSpeed;
         modZ = Input.GetAxis("Vertical") * Time.deltaTime * moveSpeed;
         
         modifier.z = modZ;
         modifier.x = modX;
 
         transform.position = Vector3.Lerp(transform.position, transform.position + modifier, Time.deltaTime * cameraSmooth);
 
         var inputZ = Input.GetAxis("Vertical");
         var inputX = Input.GetAxis("Horizontal");
         
         var angle = Mathf.Atan2(Input.GetAxis("Horizontal"), Input.GetAxis("Vertical")) * Mathf.Rad2Deg;
         transform.rotation = Quaternion.Euler(0, angle, 0);

The problem I have is that I need to determine the speed of the object to affect animation speed.

I cant use the joystick axis as it goes from -1 to +1 and I cannot use rigidbody.velocity.magnitude as I am not using forces.

Is there any way I can work out the speed of the object from a scale of 0 to 1?

Answer 1

Best Answer

Answer by MakinStuffLookGood · Jan 22, 2015 at 09:13 PM

You can't use the joystick because it goes from -1 to 1? Could you not just use Mathf.Abs(Input.GetAxis("Horizontal")) to get a value in the correct range then?

If that's no good, just store your position every frame in some variable Vector3 prevPosition and each frame you can do something like:

 float instantaneousSpeed = Vector3.Distance(transform.position, prevPosition);

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NerdRageStudios · Jan 22, 2015 at 09:26 PM 0

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Thanks Broxxar, I created the following and it works great :)

         float x = Mathf.Abs(inputX);
         float z = Mathf.Abs(inputZ);
         float s = Mathf.Max(z, x);

Answer 2

Answer by carrollh · Jan 22, 2015 at 08:07 PM

Since you have a rigidbody, why don't you just use Rigidbody.MovePosition and Rigidbody.MoveRotation? Then I think you could use the rigidbody.velocity.magnitude that you mentioned. You might need to normalize it first to get it into unit vector form. So your code might look like this:

 rigidbody.MovePosition(rigidbody.position + moveSpeed * Time.deltaTime);

 float velMag = rigidbody.velocity.magnitude;
 animator.SetFloat("Speed", velMag / moveSpeed);

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NerdRageStudios · Jan 22, 2015 at 08:49 PM 0

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Hey thanks for helping! I tried that but when I put velMag to Debug.Log its always showing 0

Any ideas?

How to determine speed of an object when using transform.position

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