一、代码自我解析
二、学习地址
三、Unity3D源代码
一、源代码自我解析
using UnityEngine;
public class CameraControl : MonoBehaviour
{
public float m_DampTime = 0.2f; // 摄像机延迟移动时间系数
public float m_ScreenEdgeBuffer = 4f; // 在最上面/下面的目标和屏幕边缘之间的空间（边缘缓冲区大小）
public float m_MinSize = 6.5f; // 正交摄像机所能看的最小尺寸
/*[HideInInspector]*/ public Transform[] m_Targets;
// 摄像机需要包含的所有目标 private Camera m_Camera; // 用于引用摄像机
private float m_ZoomSpeed; // 定义摄像机变焦的速率
private Vector3 m_MoveVelocity; // 用于相机移动时对速度进行缓冲的向量
private Vector3 m_DesiredPosition; // 相机移动的位置 private void Awake()
{
m_Camera = GetComponentInChildren<Camera>(); // 游戏一开始便使m_Camera对象获取场景中的相机
} private void FixedUpdate()
{
// 移动相机
Move(); // 改变相机的焦距大小
Zoom();
} private void Move()
{
// 找到目标到原点的平均位置所在（坦克的移动路线上的中点）
FindAveragePosition(); // 使相机光滑地移动到目标位置
transform.position = Vector3.SmoothDamp(transform.position, m_DesiredPosition, ref m_MoveVelocity, m_DampTime);
} private void FindAveragePosition()
{
Vector3 averagePos = new Vector3();
int numTargets = 0; // 检查所有的目标并将它们的位置相加（所有坦克）
for (int i = 0; i < m_Targets.Length; i++)
{
// 如果目标不存在，跳过并继续执行for循环
if (!m_Targets[i].gameObject.activeSelf)
continue; // 通过添加到平均值中，并在平均值中增加目标的数量。
averagePos += m_Targets[i].position;
numTargets++;
} // 检测目标数是否大于0若是便计算出平均的位置
if (numTargets > 0)
averagePos /= numTargets; // 保持y值不变，坦克不会飞，所以y一定不能改变
averagePos.y = transform.position.y; // 计算出来的平均位置就是相机要移动到的位置
m_DesiredPosition = averagePos;
} private void Zoom()
{
// 根据所需的位置找到所需的大小，并顺利过渡到该大小。
float requiredSize = FindRequiredSize();
m_Camera.orthographicSize = Mathf.SmoothDamp(m_Camera.orthographicSize, requiredSize, ref m_ZoomSpeed, m_DampTime);
} private float FindRequiredSize()
{
// 找到相机设备在其本地空间中移动的位置。
Vector3 desiredLocalPos = transform.InverseTransformPoint(m_DesiredPosition); // 将相机变焦大小初始值设为0
float size = 0f; // 遍历一遍相机照射目标
for (int i = 0; i < m_Targets.Length; i++)
{
// 如果目标不存在，跳过并继续执行for循环
if (!m_Targets[i].gameObject.activeSelf)
continue; // 此外，找到目标在摄像机所在的本地空间里的坐标
Vector3 targetLocalPos = transform.InverseTransformPoint(m_Targets[i].position); // 从相机的本地空间的期望位置找到目标的位置
Vector3 desiredPosToTarget = targetLocalPos - desiredLocalPos; // 从当前大小和坦克与相机的“上”或“下”距离中选择最大的一个。(位置不变或者是拉伸摄像机)
size = Mathf.Max (size, Mathf.Abs (desiredPosToTarget.y)); // 根据坦克出现在摄像机的左或右，选择当前尺寸中最大的那一个
size = Mathf.Max (size, Mathf.Abs (desiredPosToTarget.x) / m_Camera.aspect);
} // 将边缘缓冲区添加到该大小
size += m_ScreenEdgeBuffer; // 确保相机的尺寸不小于最小值
size = Mathf.Max(size, m_MinSize); return size;
} public void SetStartPositionAndSize()
{
// 找到期望位置
FindAveragePosition(); // 在没有阻尼时设置相机位置到期望位置（阻尼即相机的缓冲）个人理解类似摩擦力之类的使得相机移动更平滑
transform.position = m_DesiredPosition; m_Camera.orthographicSize = FindRequiredSize();
}
}// 以上只是自己对于该代码的理解，如有误还望指出让我及时改正。
二、学习Unity地址
https://www.youtube.com/watch?v=paLLfWd2k5A
三、Unity3D中该案例源代码：
using UnityEngine;
namespace Complete
{
public class CameraControl : MonoBehaviour
{
public float m_DampTime = 0.2f; // Approximate time for the camera to refocus.
public float m_ScreenEdgeBuffer = 4f; // Space between the top/bottom most target and the screen edge.
public float m_MinSize = 6.5f; // The smallest orthographic size the camera can be.
[HideInInspector] public Transform[] m_Targets; // All the targets the camera needs to encompass.
private Camera m_Camera; // Used for referencing the camera.
private float m_ZoomSpeed; // Reference speed for the smooth damping of the orthographic size.
private Vector3 m_MoveVelocity; // Reference velocity for the smooth damping of the position.
private Vector3 m_DesiredPosition; // The position the camera is moving towards.
private void Awake ()
{
m_Camera = GetComponentInChildren<Camera> ();
}
private void FixedUpdate ()
{
// Move the camera towards a desired position.
Move ();
// Change the size of the camera based.
Zoom ();
}
private void Move ()
{
// Find the average position of the targets.
FindAveragePosition ();
// Smoothly transition to that position.
transform.position = Vector3.SmoothDamp(transform.position, m_DesiredPosition, ref m_MoveVelocity, m_DampTime);
}
private void FindAveragePosition ()
{
Vector3 averagePos = new Vector3 ();
int numTargets = 0;
// Go through all the targets and add their positions together.
for (int i = 0; i < m_Targets.Length; i++)
{
// If the target isn't active, go on to the next one.
if (!m_Targets[i].gameObject.activeSelf)
continue;
// Add to the average and increment the number of targets in the average.
averagePos += m_Targets[i].position;
numTargets++;
}
// If there are targets divide the sum of the positions by the number of them to find the average.
if (numTargets > 0)
averagePos /= numTargets;
// Keep the same y value.
averagePos.y = transform.position.y;
// The desired position is the average position;
m_DesiredPosition = averagePos;
}
private void Zoom ()
{
// Find the required size based on the desired position and smoothly transition to that size.
float requiredSize = FindRequiredSize();
m_Camera.orthographicSize = Mathf.SmoothDamp (m_Camera.orthographicSize, requiredSize, ref m_ZoomSpeed, m_DampTime);
}
private float FindRequiredSize ()
{
// Find the position the camera rig is moving towards in its local space.
Vector3 desiredLocalPos = transform.InverseTransformPoint(m_DesiredPosition);
// Start the camera's size calculation at zero.
float size = 0f;
// Go through all the targets...
for (int i = 0; i < m_Targets.Length; i++)
{
// ... and if they aren't active continue on to the next target.
if (!m_Targets[i].gameObject.activeSelf)
continue;
// Otherwise, find the position of the target in the camera's local space.
Vector3 targetLocalPos = transform.InverseTransformPoint(m_Targets[i].position);
// Find the position of the target from the desired position of the camera's local space.
Vector3 desiredPosToTarget = targetLocalPos - desiredLocalPos;
// Choose the largest out of the current size and the distance of the tank 'up' or 'down' from the camera.
size = Mathf.Max(size, Mathf.Abs(desiredPosToTarget.y));
// Choose the largest out of the current size and the calculated size based on the tank being to the left or right of the camera.
size = Mathf.Max(size, Mathf.Abs(desiredPosToTarget.x) / m_Camera.aspect);
}
// Add the edge buffer to the size.
size += m_ScreenEdgeBuffer;
// Make sure the camera's size isn't below the minimum.
size = Mathf.Max (size, m_MinSize);
return size;
}
public void SetStartPositionAndSize ()
{
// Find the desired position.
FindAveragePosition ();
// Set the camera's position to the desired position without damping.
transform.position = m_DesiredPosition;
// Find and set the required size of the camera.
m_Camera.orthographicSize = FindRequiredSize ();
}
}
}
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