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各种Camera,总有一款适合你(二)

时间:2014-09-26 15:00:18      阅读:339      评论:0      收藏:0      [点我收藏+]

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  在实际的项目开发中,一般需要程序抽象出一些在几何意义上有明确意义的参数,这样方便策划或美术在自己的机器上进行调试。

  下面是一个可变参的地下城摄像机的简单实现:

// 第三人称摄像机,平移和旋转会同时进行平滑
public class ThirdPersonalCamera : MonoBehaviour
{
    /// Camera Control Params
    public GameObject Target = null;
    public float Distance = 10f;
    public float RotateX = 0f;                                  // pitch 俯仰
    public float RotateY = 0f;                                  // yaw 偏航
    public float SmoothTime = 0.01f;                            // 平滑时间,默认为1s
    public float ScrollWheelSpeed = 1000f;                      // 中轴调整速度
    public Vector3 TargetOffset = Vector3.zero;                 // 目标偏移量

    private Vector3 Velocity = Vector3.zero;                    // 平滑初速度
    private Vector3 Offset = Vector3.zero;                      // 根据上面三个变量计算出
    private const float MinDistance = 5f;                       // 镜头最近距离
    private const float MaxDistance = 100f;                     // 镜头最远距离

    void Start()
    {
        if (Target == null) return;
    }

    public void Shake()
    {
        StartCoroutine("ShakeCoroutine");
    }

    void LateUpdate()
    {
        if (Target == null) return;

        UpdateDistance();

        float radX = Mathf.Deg2Rad * RotateX;
        float radY = Mathf.Deg2Rad * RotateY;

        Offset.x = Distance * Mathf.Cos(radX) * Mathf.Cos(radY);
        Offset.z = Distance * Mathf.Cos(radX) * Mathf.Sin(radY);
        Offset.y = Distance * Mathf.Sin(radX);

        Vector3 targetPos = Target.transform.position + Offset + TargetOffset;
        transform.position = Vector3.SmoothDamp(transform.position, targetPos, ref Velocity, SmoothTime);

        transform.LookAt(Target.transform.position + TargetOffset);
    }

    private void UpdateDistance()
    {
        float horizontal = Input.GetAxis("Mouse ScrollWheel") * ScrollWheelSpeed * Time.deltaTime;
        Distance -= horizontal;
    }

}

  可以看到抽象出的控制参数主要包括:摄像机分别绕X轴和Y轴的旋转、摄像机距离角色的距离、以及用来控制平滑时间的参数。

  注意,上面这段代码的实现中,position和rotation是同时进行平滑的,下面来看另外一种实现:

using UnityEngine;
using System.Collections;

[ExecuteInEditMode]
public class MyDungeonCamera : MonoBehaviour
{
    /// [摄像机控制参数]
    public GameObject Target = null;
    public float RotateX = 0f;                                  // pitch 俯仰
    public float RotateY = 0f;                                  // yaw 偏航
    public float Distance = 10f;                                // 摄像机远近
    public float MoveSmoothTime = 0.3f;                         // 位置平滑时间,默认为1s
    public float RotateSmoothTime = 0.3f;                       // 旋转平滑时间
    public float ScrollWheelSpeed = 1000f;                      // 中轴调整速度
    public Vector3 TargetOffset = Vector3.zero;                 // 目标偏移量

    private Vector3 Velocity = Vector3.zero;                    // 平滑初速度
    private Vector3 Offset = Vector3.zero;                      // 根据上面三个变量计算出
    private const float MinDistance = 5f;                       // 镜头最近距离
    private const float MaxDistance = 100f;                     // 镜头最远距离
    private Quaternion tmpRotation = Quaternion.identity;
    private Vector3 tmpPosition = Vector3.zero;

    private float RotateDamping
    {
        get
        {
            if (RotateSmoothTime <= 0f) RotateSmoothTime = 0.001f;
            return 1f / RotateSmoothTime;
        }
    }

    void LateUpdate()
    {
        if (Target == null) return;

        tmpRotation = transform.rotation;
        tmpPosition = transform.position;

        UpdateDistance();
        UpdateRotation();
        UpdatePosition();

        transform.rotation = tmpRotation;
        transform.position = tmpPosition;
    }

    private void UpdateRotation()
    {
        if (!NeedRotate()) return;

        Quaternion wantedRotation = Quaternion.Euler(RotateX, RotateY, 0f);
        // 旋转采用球形插值
        tmpRotation = Quaternion.Slerp(tmpRotation, wantedRotation, Time.deltaTime * RotateDamping);
    }

    private void UpdatePosition()
    {
        // 如果有旋转插值,则位置根据旋转变换;否则,位置自己进行插值过渡
        if (!NeedRotate())
        {
            Offset = Quaternion.Euler(RotateX, RotateY, 0f) * Vector3.forward * Distance;
            Vector3 wantedPos = Target.transform.position - Offset + TargetOffset;
            // 位置采用平滑阻尼过渡
            tmpPosition = Vector3.SmoothDamp(tmpPosition, wantedPos, ref Velocity, MoveSmoothTime);
        }
        else
        {
            Offset = tmpRotation * Vector3.forward * Distance;
            tmpPosition = Target.transform.position - Offset + TargetOffset;
        }
    }

    private void UpdateDistance()
    {
        float horizontal = Input.GetAxis("Mouse ScrollWheel") * ScrollWheelSpeed * Time.deltaTime;
        Distance -= horizontal;
        Distance = Mathf.Clamp(Distance, MinDistance, MaxDistance);
    }

    private bool NeedRotate()
    {
        Vector3 eulerAngles = transform.rotation.eulerAngles;
        return !(FloatEqual(eulerAngles.x, RotateX) && FloatEqual(eulerAngles.y, RotateY));
    }

    public static bool FloatEqual(float value1, float value2)
    {
        float ret = value1 - value2;
        return ret > -0.0005f && ret < 0.0005f;
    }

}

  这个实现中,有几点需要注意的:

  (1)rotation使用四元素球形插值,这样保证每次旋转的角速度是恒定的,不过两次旋转各自的角速度不相等,这里可以改进;

  (2)position使用Vector3.SmoothDamp进行平滑阻尼过渡效果会比较好;

  (3)浮点数相等判断,不要直接用等号哟;

  (4)当同时有rotation和position时,以rotation为主;

  (5)是否需要旋转的判断,只有需要的时候才走旋转逻辑,这样可以减轻Update的压力。

  摄像机振动脚本:

using UnityEngine;
using System.Collections;

public class ShakeCamera : MonoBehaviour 
{
    public float ShakeTime = 1f;                                // 时间
    public float ShakeStrength = 1f;                            // 振幅
    public int ShakeRate = 10;                                  // 频率

    public void Shake()
    {
        StartCoroutine("ShakeCoroutine");
    }

    public void Shake(float time, float strength, int rate)
    {
        ShakeTime = time;
        ShakeStrength = strength;
        ShakeRate = rate;
        StartCoroutine("ShakeCoroutine");
    }

    IEnumerator ShakeCoroutine()
    {
        // 此处需要先用临时变量记录相关参数值,以便能够实现多次重叠shake
        float startTime = Time.time;
        float endTime = startTime + ShakeTime;
        float interval = 1f / (float)ShakeRate;
        float strength = ShakeStrength;
        float timeCount = 0f;

        while (Time.time < endTime)
        {
            timeCount += Time.deltaTime;
            if (timeCount > interval)
            {
                // 获取随机位置
                Vector3 offset = Random.insideUnitSphere * strength;
                transform.position += offset;
                timeCount -= interval;
            }
            yield return null;
        }
    }

}

 

各种Camera,总有一款适合你(二)

标签:style   blog   color   io   os   使用   ar   for   sp   

原文地址:http://www.cnblogs.com/sifenkesi/p/3994594.html

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