unity 不能隐式地将类型 float' 转换为 bool' 也使相机变焦？

Question

我使用 C#，我是新手。我正在尝试为统一游戏制作缩放功能。这是我的代码（到目前为止我有）：

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Zoom : MonoBehaviour
{
    public Camera cam;
    public float zoom_speed = 20f;

    // Update is called once per frame
    void Update ()
    {
        if(Input.GetAxis("Mouse ScrollWheel"))
        {
            cam.fieldOfView = zoom_speed;
        }
    }
}

但是，当我将鼠标悬停在 if(Input.GetAxis("Mouse Scrollwheel")) 上时，我收到错误消息“无法将类型 float 隐式转换为 bool任何关于如何使缩放程序工作的建议将不胜感激。

Answer 1

Input.GetAxis("Mouse ScrollWheel");脚本return一个浮点值。

The value will be in the range -1...1 for keyboard and joystick input. If the axis is setup to be delta mouse movement, the mouse delta is multiplied by the axis sensitivity and the range is not -1...1.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Zoom : MonoBehaviour
{
    public Camera cam;
    public float zoom_speed = 20f;

    // Update is called once per frame
    void Update ()
    {
         float d = Input.GetAxis("Mouse ScrollWheel");
         if (d > 0f)
         {
            //Positive value
            //Scroll up
            cam.fieldOfView += zoom_speed;
         }
         else if (d < 0f)
         {
            //Negative value
            //Scroll down
            cam.fieldOfView -= zoom_speed;
         }

    }
}

Answer 2

补充 0xBFE1A8 的答案，您甚至不需要使用 if...else 语句，因为该值将在 - 范围内1...1，只需将 Input.GetAxis("Mouse ScrollWheel") 值乘以 zoom_speed。我还建议您将视野限制在您定义的最小值和最大值之间。

float scroll = Input.GetAxis("Mouse ScrollWheel");
cam.fieldOfView = Mathf.Clamp(cam.fieldOfView + zoom_speed * scroll * Time.deltaTime, minFieldOfView, maxFieldOfView);

unity 不能隐式地将类型 float' 转换为 bool' 也使相机变焦？

unity cannot implicitly convert type float' to bool' also Make the camera zoom?

c#

zooming

unity3d