减慢刚体速度

Question

我添加了基于 的前向力GetAxis ("Vertical")和高达 的速度调节器normal max speed。

我还允许“速度提升”，在正常附加力的基础上增加更多的力，最高可达boosted max speed。

我遇到的困难是一旦升压期结束就减慢物体的速度

因此，基本上，如果您将速度提升到比正常最大速度更快的速度，并且您无法再进行速度提升，请将物体减慢回正常最大速度。

这是我到目前为止得到的：

    float velocity;
    float magnitude = myRigidBody.velocity.magnitude;
    float vertical = Input.GetAxis ("Vertical");
    if (Input.GetKeyUp(KeyCode.LeftShift)) {
        boost = false;
    }
    if (Input.GetKeyDown (KeyCode.LeftShift)) {
        boost = true;
    }
    if (!boost) {
        velocity = vertical * speed;
        Vector3 force = myRigidBody.transform.forward * velocity;
        if (magnitude + force.sqrMagnitude < normalMaxSpeed) { 
            myRigidBody.drag = 0f;
            myRigidBody.AddForce (force, ForceMode.Impulse);
        } else if (magnitude + force.sqrMagnitude >= maxTrust + 50) { 
            myRigidBody.drag = 1.5f;
        }
    } else if ( magnitude < boostedMaxSpeed) { 
        velocity = vertical * (speed + speedBoost);
        myRigidBody.AddForce (myRigidBody.transform.forward * velocity, ForceMode.Impulse);

这有些有效，但除了改变阻力之外，必须有更好的解决方案。

Answer 1

除了改变阻力之外，还有其他方法可以做到这一点。您只需尝试一下，看看哪一种效果最好。

1.改变拖动方式

myRigidBody.drag = 20f;

2 .向相反的速度添加力。

public Rigidbody myRigidBody;
void FixedUpdate()
{
    Vector3 oppositeVelocity = -myRigidBody.velocity;
    myRigidBody.AddRelativeForce(oppositeVelocity);
}

3.Decrement or Lerp the current velocity back to the normal force.

public Rigidbody myRigidBody;
Vector3 normalForce;

void Start()
{
    normalForce = new Vector3(50, 0, 0);

    //Add force  
    myRigidBody.velocity = new Vector3(500f, 0f, 0f);
    //OR
    //myRigidBody.AddForce(new Vector3(500f, 0f, 0f));
}

void FixedUpdate()
{
    //Go back to normal force within 2 seconds
    slowDown(myRigidBody, normalForce, 2);
    Debug.Log(myRigidBody.velocity);
}

bool isMoving = false;

void slowDown(Rigidbody rgBody, Vector3 normalForce, float duration)
{
    if (!isMoving)
    {
        isMoving = true;
        StartCoroutine(_slowDown(rgBody, normalForce, duration));
    }
}

IEnumerator _slowDown(Rigidbody rgBody, Vector3 normalForce, float duration)
{
    float counter = 0;
    //Get the current position of the object to be moved
    Vector3 currentForce = rgBody.velocity;

    while (counter < duration)
    {
        counter += Time.deltaTime;
        rgBody.velocity = Vector3.Lerp(currentForce, normalForce, counter / duration);
        yield return null;
    }

    isMoving = false;
}

4.Change the dynamic friction of the Physics Material. You can't use this method because it requires collider which you don't have.

//Get the PhysicMaterial then change its dynamicFriction
PhysicMaterial pMat = myRigidBody.GetComponent<Collider>().material;
pMat.dynamicFriction = 10;

It's really up to you to experiment and decide which one works best for you. They are useful depending on what type of game you are making. For example, #4 is mostly used when rolling a ball because it uses physics material which requires frequent collision to actually work.

The method used in #3 gives you control over how long the transition should happen. If you need to control that then that's the choice.