【unity小技巧】实现没有动画的FPS武器摇摆和摆动效果

using UnityEngine;

// 武器摆动脚本
public class SwayNBobScript : MonoBehaviour
{
    [Header("Sway")]
    public float step = 0.01f;  // 摆动步长
    public float maxStepDistance = 0.06f;  // 最大步长距离
    Vector3 swayPos;  // 摆动位置

    [Header("Sway Rotation")]
    public float rotationStep = 4f;  // 摆动旋转步长
    public float maxRotationStep = 5f;  // 最大旋转步长
    Vector3 swayEulerRot;  // 摆动旋转角度

    public float smooth = 10f;  // 平滑移动速度
    float smoothRot = 12f;  // 平滑旋转速度

    [Header("Bobbing")]
    public float speedCurve;  // 速度曲线参数
    float curveSin { get => Mathf.Sin(speedCurve); }  // 曲线正弦值
    float curveCos { get => Mathf.Cos(speedCurve); }  // 曲线余弦值

    public Vector3 travelLimit = Vector3.one * 0.025f;  // 移动限制
    public Vector3 bobLimit = Vector3.one * 0.01f;  // 摆动限制
    Vector3 bobPosition;  // 摆动位置偏移量

    public float bobExaggeration;  // 摆动夸张系数

    [Header("Bob Rotation")]
    public Vector3 multiplier;  // 摆动旋转系数
    Vector3 bobEulerRotation;  // 摆动旋转角度

    void Update()
    {
        GetInput();

        Sway();
        SwayRotation();
        BobOffset();
        BobRotation();

        CompositePositionRotation();
    }


    Vector2 walkInput;  // 行走输入
    Vector2 lookInput;  // 视角输入

    // 获取输入
    void GetInput()
    {
        walkInput.x = Input.GetAxis("Horizontal");
        walkInput.y = Input.GetAxis("Vertical");
        walkInput = walkInput.normalized;

        lookInput.x = Input.GetAxis("Mouse X");
        lookInput.y = Input.GetAxis("Mouse Y");
    }


    // 摆动
    void Sway()
    {
        Vector3 invertLook = lookInput * -step;
        invertLook.x = Mathf.Clamp(invertLook.x, -maxStepDistance, maxStepDistance);
        invertLook.y = Mathf.Clamp(invertLook.y, -maxStepDistance, maxStepDistance);
        swayPos = invertLook;
    }

    // 摆动旋转
    void SwayRotation()
    {
        Vector2 invertLook = lookInput * -rotationStep;
        invertLook.x = Mathf.Clamp(invertLook.x, -maxRotationStep, maxRotationStep);
        invertLook.y = Mathf.Clamp(invertLook.y, -maxRotationStep, maxRotationStep);
        swayEulerRot = new Vector3(invertLook.y, invertLook.x, invertLook.x);
    }

    // 合成位置和旋转部分
    void CompositePositionRotation()
    {
        transform.localPosition = Vector3.Lerp(transform.localPosition, swayPos + bobPosition, Time.deltaTime * smooth);
        transform.localRotation = Quaternion.Slerp(transform.localRotation, Quaternion.Euler(swayEulerRot) * Quaternion.Euler(bobEulerRotation), Time.deltaTime * smoothRot);
    }

    // 摆动偏移
    void BobOffset()
    {
        speedCurve += Time.deltaTime * (MovementScript.Instance.isGround ? (Input.GetAxis("Horizontal") + Input.GetAxis("Vertical")) * bobExaggeration : 1f) + 0.01f;

        bobPosition.x = (curveCos * bobLimit.x * (MovementScript.Instance.isGround ? 1 : 0)) - (walkInput.x * travelLimit.x);
        bobPosition.y = (curveSin * bobLimit.y) - (Input.GetAxis("Vertical") * travelLimit.y);
        bobPosition.z = -(walkInput.y * travelLimit.z);
    }

    // 摆动旋转
    void BobRotation()
    {
        bobEulerRotation.x = (walkInput != Vector2.zero ? multiplier.x * (Mathf.Sin(2 * speedCurve)) : multiplier.x * (Mathf.Sin(2 * speedCurve) / 2));
        bobEulerRotation.y = (walkInput != Vector2.zero ? multiplier.y * curveCos : 0);
        bobEulerRotation.z = (walkInput != Vector2.zero ? multiplier.z * curveCos * walkInput.x : 0);
    }
}

public SwayNBobScript swayNBobScript;

private void Update()
{
  DetermineAim();
}

//瞄准
void DetermineAim(){
  swayNBobScript.enabled = true;
  if (Input.GetMouseButton(1)){
      swayNBobScript.enabled = false;
  } 
}