如何将矢量的方向校正为相机的旋转？答案

【问题标题】：How do I correct the direction of my vector to the rotation of the camera?如何将矢量的方向校正为相机的旋转？
【发布时间】：2017-02-23 06:46:12
【问题描述】：

对于 3D 第一人称控制器游戏，我将屏幕上的滑动转换为方向矢量。一个物体被射向这个方向。我的相机可以根据虚拟操纵杆的输入进行旋转。当我不旋转并使用滑动拍摄对象时，它会朝正确的方向移动。但是，当我旋转相机时，它不会朝预期的方向移动。方向应该适应相机的旋转。

如何将矢量的方向校正为相机的旋转？

PS: 私信我进一步说明

//Converting swipe direction to 3D direction
public class TouchPair
{
    public Vector2 startPos;
    public int fingerId;
}

private TouchPair touchPair;

void Update()
{
  foreach (Touch touch in Input.touches)
  {
      Vector2 touchPos = touch.position;

      if (touch.phase == TouchPhase.Began)
      {
         Ray ray = cam.ScreenPointToRay(touchPos);
         RaycastHit hit;

         if (Physics.Raycast(ray, out hit))
         {
            //The player is wielding a bomb that is visible on the screen.
            //only swipes that start from this object should count 
            if (hit.transform.tag == "Bomb")
            {
                touchPair = new TouchPair();
                touchPair.startPos = touchPos;
                touchPair.fingerId = touch.fingerId;
            }
          }
      }
      else if (touch.phase == TouchPhase.Ended)
      {          
         if (touchPair.fingerId == touch.fingerId)
         {
            Vector2 endPos = touchPos;
            Vector2 swipeDirectionRaw = endPos - touchPair.startPos;
            float magnitude = swipeDirectionRaw.magnitude;
            if (magnitude >= minSwipeLength)
            {
                  BombController BombController =                                                           GameObject.FindWithTag("Bomb").GetComponent<BombController>();
                            BombController.Throw(swipeDirectionRaw.normalized, magnitude);
            }
         }
      }
  }
}     

public void Throw(Vector2 direction, float magnitude)
{

    //Setup variables for throw
    throwDirection = new Vector3(direction.x, 0.0f, direction.y);
    throwSpeed = magnitude * throwForce;
}

【问题讨论】：

“我正在将屏幕上的滑动转换为方向向量。” -- 你能告诉我们这样做的代码吗？我假设如果您使用Camera.ScreenToWorldPoint，那么您不会有问题。

标签： c# unity3d

【解决方案1】：

当 touch.phase == TouchPhase.Ended 时，您需要使用地面进行光线投射，然后从您的角色获取方向到 raycast.hit。

Raycasthit hitInfo;
Physic.Raycast;

【讨论】：

【解决方案2】：

我必须得到相机的视图向量。通过取角的数量在玩家的前方和相机的视角矢量之间，接收到获得正确方向矢量所需的角度数量。最后将拍摄方向旋转这个角度。

                    Vector2 endPos = touchPos;
                    Vector2 swipeDirectionRaw = endPos - touchPair.startPos;
                    float magnitude = swipeDirectionRaw.magnitude;
                    swipeDirectionRaw.Normalize();
                    if (magnitude >= minSwipeLength)
                    {
                        GameObject player = GameObject.FindWithTag("Player");
                        Vector3 shootOrigin = player.transform.position;
                        Vector3 uncorrectedShootDirection = new Vector3(swipeDirectionRaw.x, 0.0f, swipeDirectionRaw.y);

                        Vector3 originVector = player.transform.forward;
                        Vector3 viewVector = cam.transform.forward;

                        //Shoot direction gets corrected by angle between origin- and view vector
                        float angleBetweenOriginAndView = Vector3.Angle(originVector, viewVector);

                //There is no clockwise or counter-clockwise in 3d space, 
                //hence mirroring is needed. In my case it's done to what suits my needs
                            if (viewVector.x < 0.0f)
                            {
                                angleBetweenOriginAndView *= -1f;
                            }

                        Vector3 correctedShootDirection = Quaternion.Euler(0, angleBetweenOriginAndView, 0) * uncorrectedShootDirection;
                    }

                    touchPair = null;
                }

【讨论】：