unity笔记_贝塞尔曲线

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

public class BezierCurve
{

    public enum BezierType
    {
        /// <summary>
        /// 一阶
        /// </summary>
        line,
        /// <summary>
        /// 二阶
        /// </summary>
        Quardatic,
        /// <summary>
        /// 三阶
        /// </summary>
        Cubic
    }
    public Transform[] BezierHandle;
    public BezierType type;

    public BezierCurve(Transform[] BezierHandle, BezierType type)
    {
        this.BezierHandle = BezierHandle;
        this.type = type;
    }

    public Vector3 GetCurrentBezier(float t)
    {
        switch (type)
        {
            case BezierType.line:
                return lineBezier(t);
            case BezierType.Quardatic:
                return QuardaticBezier(t);
            case BezierType.Cubic:
                return CubicBezier(t);
            default:
                return Vector3.zero;
        }
    }
    public void SetCurrentBezier(Transform[] handles)
    {
        if (handles.Length > BezierHandle.Length)
        {
            for (int i = 0; i < BezierHandle.Length; i++)
            {
                BezierHandle[i] = handles[i];
            }
        }
        else
        {
            for (int i = 0; i < handles.Length; i++)
            {
                BezierHandle[i] = handles[i];
            }
        }
    }
    public void SetCurrentBezier(Transform[] handles, BezierType bezierType)
    {
        type = bezierType;
        SetCurrentBezier(handles);
    }
    /// <summary>
    /// 一阶贝塞尔曲线
    /// </summary>
    /// <param name="t"></param>
    /// <returns></returns>
    Vector3 lineBezier(float t)
    {
        if (BezierHandle.Length < 2) throw new System.Exception("使用一阶贝塞尔曲线必须有两个控制点");
        Vector3 a = BezierHandle[0].position;
        Vector3 b = BezierHandle[1].position;
        return a + (b - a) * t;
    }

    /// <summary>
    /// 二阶贝塞尔曲线
    /// </summary>
    /// <param name="t"></param>
    /// <returns></returns>
    Vector3 QuardaticBezier(float t)
    {
        if (BezierHandle.Length < 3) throw new System.Exception("使用二阶贝塞尔曲线必须有三个控制点");
        Vector3 a = BezierHandle[0].position;
        Vector3 b = BezierHandle[1].position;
        Vector3 c = BezierHandle[2].position;

        Vector3 aa = a + (b - a) * t;
        Vector3 bb = b + (c - b) * t;
        return aa + (bb - aa) * t;
    }
    /// <summary>
    /// 三阶贝塞尔
    /// </summary>
    /// <param name="t"></param>
    /// <returns></returns>
    Vector3 CubicBezier(float t)
    {
        if (BezierHandle.Length < 4) throw new System.Exception("使用三阶贝塞尔曲线必须有四个个控制点");
        Vector3 a = BezierHandle[0].position;
        Vector3 b = BezierHandle[1].position;
        Vector3 c = BezierHandle[2].position;
        Vector3 d = BezierHandle[3].position;

        Vector3 aa = a + (b - a) * t;
        Vector3 bb = b + (c - b) * t;
        Vector3 cc = c + (d - c) * t;

        Vector3 aaa = aa + (bb - aa) * t;
        Vector3 bbb = bb + (cc - bb) * t;
        return aaa + (bbb - aaa) * t;
    }




    public static Vector3 GetlineBezier(Vector3 a, Vector3 b, float t)
    {
        return a + (b - a) * t;
    }
    public static Vector3 GetQuardaticBezier(Vector3 a, Vector3 b, Vector3 c, float t)
    {

        Vector3 aa = a + (b - a) * t;
        Vector3 bb = b + (c - b) * t;
        return aa + (bb - aa) * t;
    }
    public static Vector3 GetCubicBezier(Vector3 a, Vector3 b, Vector3 c, Vector3 d, float t)
    {
        Vector3 aa = a + (b - a) * t;
        Vector3 bb = b + (c - b) * t;
        Vector3 cc = c + (d - c) * t;

        Vector3 aaa = aa + (bb - aa) * t;
        Vector3 bbb = bb + (cc - bb) * t;
        return aaa + (bbb - aaa) * t;
    }

}

参考博文：

【游戏开发进阶】玩转贝塞尔曲线，教你在Unity中画Bezier贝塞尔曲线（二阶、三阶），手把手教你推导公式_linxinfa的专栏-CSDN博客_bezier.method.ac攻略

【游戏开发实战】Unity实现类似GitHub地球射线的效果（LineRenderer | 贝塞尔曲线）_linxinfa的专栏-CSDN博客