c# - 最大化缩放距离以适合2个对象

我会避免使用角度，而不会使用向量和平面。

确定黄点在相机的哪一侧：

Camera cam = cameraComp;
Transform camTransform = cam.transform;
Vector3 yellowPos = yellowPoint.transform.position;

// <0 if on left, >0 if on right
float camDirection = Vector3.Dot(camTransform.right, yellowPos - camTransform.position);

// if it's directly straight ahead, do nothing.
if (Mathf.Approximately(camDirection, 0f)) return;

在黄点的同一侧找到相机视口边缘的光线。视口中的高度无关紧要。

Ray edgeRay = cam.ViewportPointToRay(camDirection < 0f ? Vector3.zero : Vector3.right);

定义垂直于相机右侧并经过黄点位置的代数平面（而非物理平面）：

Plane yellowPlane = new Plane(camTransform.right, yellowPos);

使用代数射线投射（不是物理射线投射）找到射线与平面的交点：

float raycastDistance;
if (! yellowPlane.Raycast(edgeRay, out raycastDistance)) return; // should not return

Vector3 raycastPoint = edgeRay.GetPoint(raycastDistance);

找到相交点到yellowPoint位置的差，然后对照相机的向前方向进行点积运算，以查找如何沿照相机的向前方向移动它：

float forwardDelta = Vector3.Dot(camTransform.forward, yellowPos - raycastPoint);

camTransform.Translate(0f, 0f, forwardDelta);

因此，总共：

Camera cam = cameraComp;
Transform camTransform = cam.transform;
Vector3 yellowPos = yellowPoint.transform.position;

// <0 if on left, >0 if on right
float camDirection = Vector3.Dot(camTransform.right, yellowPos - camTransform.position);

// if it's directly straight ahead, do nothing.
if (Mathf.Approximately(camDirection, 0f)) return;

Ray edgeRay = cam.ViewportPointToRay(camDirection < 0f ? Vector3.zero : Vector3.right);

Plane yellowPlane = new Plane(camTransform.right, yellowPos);

float raycastDistance;
if (! yellowPlane.Raycast(edgeRay, out raycastDistance)) return; // should not return

Vector3 raycastPoint = edgeRay.GetPoint(raycastDistance);

float forwardDelta = Vector3.Dot(camTransform.forward, yellowPos - raycastPoint);

camTransform.Translate(0f, 0f, forwardDelta);

这种方法的好处是，无论相机的方向如何，还是相机上的点的相对位置如何，它都可以工作。