Unity胶囊体的碰撞检测实现

可选是否打开矩阵变换，支持xyz三种朝向

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

public class CapsuleDetection : MonoBehaviour
{
    public enum Axis { X, Y, Z }
    public Transform comparePointTransform;
    public float radius;
    public float height;
    public Axis axis;
    public bool enableMatrix;


    bool ExecuteDetection()
    {
        if (comparePointTransform == null) return false;

        var result = false;
        var axisIndex = (int)axis;

        var comparePoint = comparePointTransform.position;
        var pointA = Vector3.zero;
        var pointB = Vector3.zero;

        if (enableMatrix)
        {
            comparePoint = transform.InverseTransformPoint(comparePoint);
            pointA[axisIndex] -= height - radius;
            pointB[axisIndex] += height - radius;
        }
        else
        {
            pointA = transform.position;
            pointB = transform.position;

            pointA[axisIndex] -= height - radius;
            pointB[axisIndex] += height - radius;
        }

        if (comparePoint[axisIndex] < pointA[axisIndex])
        {
            if (Vector3.Distance(comparePoint, pointA) <= radius)
            {
                result = true;
            }
        }

        else if (comparePoint[axisIndex] > pointB[axisIndex])
        {
            if (Vector3.Distance(comparePoint, pointB) <= radius)
            {
                result = true;
            }
        }
        else
        {
            var tmpPos = enableMatrix ? Vector3.zero : transform.position;
            tmpPos[axisIndex] = comparePoint[axisIndex];

            if (Vector3.Distance(comparePoint, tmpPos) <= radius)
            {
                result = true;
            }
        }

        return result;
    }

    void OnDrawGizmos()
    {
        var color = Color.blue;

        if (ExecuteDetection())
        {
            color = Color.red;
        }

        var axisIndex = (int)axis;
        var pos1 = Vector3.zero;
        var pos2 = Vector3.zero;

        if (enableMatrix)
        {
            Gizmos.matrix = transform.localToWorldMatrix;
            pos1[axisIndex] -= height;
            pos2[axisIndex] += height;
        }
        else
        {
            pos1 = transform.position;
            pos2 = transform.position;

            pos1[axisIndex] -= height;
            pos2[axisIndex] += height;
        }

        DebugExtension.DrawCapsule(pos1, pos2, color, radius);
    }
}

绘制胶囊体使用DebugExtension插件，在资源商店可以免费下载