C# 类雷击游戏中的问题实例化块

我试图用光线投射实例化像Minecraft这样的块。它可以工作，但是如果我单击旋转方向与（0,0,0）不同的块，我的块将在我单击的块的相同位置生成

我的代码：

Vector3 SnappedPosition(Vector3 pointToSnap, Vector3 blockCenterPosition)
{
    Vector3 relativePosition = pointToSnap - blockCenterPosition;
    Debug.Log("pointToSnap ="+pointToSnap);
    Debug.Log("blockCenterPosition =" + blockCenterPosition);
    Debug.Log("relativePosition = pointToSnap - blockCenterPosition =" + relativePosition);
    if (relativePosition.x == 0.5) { Debug.Log("Vector.right"); return blockCenterPosition + Vector3.right; }
    if (relativePosition.x == -0.5){ Debug.Log("Vector.left"); return blockCenterPosition + Vector3.left; }
    if (relativePosition.y == 0.5) { Debug.Log("Vector.up"); return blockCenterPosition + Vector3.up; }
    if (relativePosition.y == -0.5) { Debug.Log("Vector.down"); return blockCenterPosition + Vector3.down; }
    if (relativePosition.z == 0.5) { Debug.Log("Vector.forwad"); return blockCenterPosition + Vector3.forward; }
    if (relativePosition.z == -0.5) { Debug.Log("Vector.back"); return blockCenterPosition + Vector3.back; }
    Debug.Log("Vector3.zero"); 
    return Vector3.zero;  // error (should not occur)
        
}
void Start()
{
    hand = dust;
    // to avoid collision with player camera during raycast
    playerMask = ~LayerMask.GetMask("Player"); // everything except the player mask
}

void Update()
{
    if (Input.GetKeyDown(KeyCode.Mouse1))  // right click --> place block
    {
        RaycastHit hit;
        Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);
        if (Physics.Raycast(ray, out hit, 100.0f))
        {
            Vector3 pointToSnap = hit.point;
            Vector3 blockCenterPosition = hit.collider.transform.localPosition;
            Vector3 instantiatePosition = SnappedPosition(pointToSnap, blockCenterPosition);
            Debug.Log("instatiatePosition = blockCenterPosition + Vector " + instantiatePosition);
            Instantiate(hand, instantiatePosition, Quaternion.identity);  
        }
    }
}

调试： 放置2个街区。 运行时不更改旋转：工作

• pointToSnap=（0.0，-0.5,0.0）
• blockCenterPosition=（0.0,0.0,0.0）
• 相对位置=点捕捉-区块中心位置=（0.0,0.5,0.0）
• 向量机
• instatiatePosition=区块中心位置+矢量（矢量向上）= (0.0,1.0,0.0);

调试： 放置2个街区。 运行时更改旋转（90,0,0）：不工作

• pointToSnap=（0.2，-0.5,0.0）
• blockCenterPosition=（0.0,0.0,0.0）
• 相对位置=点捕捉-区块中心位置=（0.2,0.5,0.0）

---

• Vector.zero（如果relativePosition.y为0.5，为什么？正确答案是Vector.up）从不使用

  ==

  直接比较

  浮点值。由于
  5*0.2f/10f
  可能是
  0.9999999
  或
  1.0000000001
  ，因此检查
  ==1f
  将失败
  
  因此，您总是希望检查它是否位于某个范围内，例如
  
  if(Mathf.Abs(a - b) <= threshold)
  
  基本上等于做
  
  if(Mathf.Abs(a - b) <= Mathf.Epsilon)
  
  if（Mathf.Abs（a-b）
  if(Mathf.Abs(a - b) <= Mathf.Epsilon)