【Unity 3D游戏开发学习笔记】粒子光环

来源：互联网发布：淘宝开店发布商品编辑：程序博客网时间：2024/04/27 07:43

实现如下图的粒子光环：
参考网站：http://i-remember.fr/en
思路：
首先声明定义一个类用于存储每个粒子的半径和角度

public class particleClass {    public float radius = 0.0f; // initialize    public float angle = 0.0f; // initialize    public particleClass(float radius_, float angle_)    {        radius = radius_;        angle = angle_;    }}

定义声明一些需要用到的变量，如最大粒子数目，粒子的数组和存储粒子半径和角度类的数组，内环和外环的半径，粒子旋转的速度和分组，分组用于确定粒子顺时针或逆时针旋转。

public int maxParticlesNum = 6000; // the max number of particlespublic ParticleSystem particleSystem;private ParticleSystem.Particle[] particlesArray;private particleClass[] paticleObject;public float minRadius = 3.5f; // inner race radiuspublic float maxRadius = 10.0f; // outer race radiuspublic float speed = 0.23f; // the speed of particlespublic int group = 2; // group 1 rotates clockwise and group 2                      // rotates anticlockwise

Start函数内初始化两个数组的大小，并且获得粒子对象，然后进行遍历，对每个粒子的位置进行随机设置，但这里实际上需要使得粒子尽可能位于环的中心，也就是(maxRaidus+minRadius)/2的位置，下面是直接采用了1个算法。随后就存储每个粒子的位置信息和设置他的位置。

void Start() {        particlesArray = new ParticleSystem.Particle[maxParticlesNum];        paticleObject = new particleClass[maxParticlesNum];        particleSystem.maxParticles = maxParticlesNum;        particleSystem.Emit(maxParticlesNum);        particleSystem.GetParticles(particlesArray);        for (int i = 0; i < maxParticlesNum; i++) {             //random angle produced            float randomAngle = Random.Range(0.0f, 360.0f);            // random radius which is closed to the midRadius in a large probility produced            float midRadius = (maxRadius + minRadius) / 2;            // quote someone else's algorithm            float minRate = Random.Range(1.0f, midRadius / minRadius);            float maxRate = Random.Range(midRadius / maxRadius, 1.0f);            float randomRadius = Random.Range(minRadius * minRate, maxRadius * maxRate);            //set two arrays            // save a new particle's radius & angle            paticleObject[i] = new particleClass(randomRadius, randomAngle);            // confirm its position            particlesArray[i].position = new Vector3(randomRadius * Mathf.Cos(randomAngle), randomRadius * Mathf.Sin(randomAngle), 0.0f);        }        //set particle        particleSystem.SetParticles(particlesArray, maxParticlesNum);    }

Update函数中，采用奇数和偶数ID来分成两个组，并且按照i和group来更新他的速度（可以改其他表达式，做到每个粒子速度不会全部相同即可），然后要更新他的角度，因为角度有周期，可能超过360度，采用取余即可避免这个问题，再次更新粒子位置。

void Update() {        // run setting, devided in 2 group        for (int i = 0; i < maxParticlesNum; i++) {            if (i % 2 == 0) { // judge if this particle should be group 1                paticleObject[i].angle += (i % group + 1) * speed;            } else { // or  group 2                paticleObject[i].angle -= (i % group + 1) * speed;            }            //set new position according to the new angle            paticleObject[i].angle = paticleObject[i].angle % 360;            float new_angle = paticleObject[i].angle / 180 * Mathf.PI;            particlesArray[i].position = new Vector3(paticleObject[i].radius * Mathf.Cos(new_angle), paticleObject[i].radius * Mathf.Sin(new_angle), 0f);        }        particleSystem.SetParticles(particlesArray, maxParticlesNum);    }

Inspector设置：
这里写图片描述
运行结果：

完整代码：

using System.Collections;using System.Collections.Generic;using UnityEngine;public class ParRotation : MonoBehaviour {    public class particleClass {        public float radius = 0.0f; // initialize        public float angle = 0.0f; // initialize        public particleClass(float radius_, float angle_)        {            radius = radius_;            angle = angle_;        }    }    public int maxParticlesNum = 6000; // the max number of particles    public ParticleSystem particleSystem;    private ParticleSystem.Particle[] particlesArray;    private particleClass[] paticleObject;    public float minRadius = 3.5f; // inner race radius    public float maxRadius = 10.0f; // outer race radius    public float speed = 0.23f; // the speed of particles    public int group = 2; // group 1 rotates clockwise and group 2 rotates anticlockwise    void Start() {        particlesArray = new ParticleSystem.Particle[maxParticlesNum];        paticleObject = new particleClass[maxParticlesNum];        particleSystem.maxParticles = maxParticlesNum;        particleSystem.Emit(maxParticlesNum);        particleSystem.GetParticles(particlesArray);        for (int i = 0; i < maxParticlesNum; i++) {             //random angle produced            float randomAngle = Random.Range(0.0f, 360.0f);            // random radius which is closed to the midRadius in a large probility produced            float midRadius = (maxRadius + minRadius) / 2;            // quote someone else's algorithm            float minRate = Random.Range(1.0f, midRadius / minRadius);            float maxRate = Random.Range(midRadius / maxRadius, 1.0f);            float randomRadius = Random.Range(minRadius * minRate, maxRadius * maxRate);            //set two arrays            // save a new particle's radius & angle            paticleObject[i] = new particleClass(randomRadius, randomAngle);            // confirm its position            particlesArray[i].position = new Vector3(randomRadius * Mathf.Cos(randomAngle), randomRadius * Mathf.Sin(randomAngle), 0.0f);        }        //set particle        particleSystem.SetParticles(particlesArray, maxParticlesNum);    }    void Update() {        // run setting, devided in 2 group        for (int i = 0; i < maxParticlesNum; i++) {            if (i % 2 == 0) { // judge if this particle should be group 1                paticleObject[i].angle += (i % group + 1) * speed;            } else { // or  group 2                paticleObject[i].angle -= (i % group + 1) * speed;            }            //set new position according to the new angle            paticleObject[i].angle = paticleObject[i].angle % 360;            float new_angle = paticleObject[i].angle / 180 * Mathf.PI;            particlesArray[i].position = new Vector3(paticleObject[i].radius * Mathf.Cos(new_angle), paticleObject[i].radius * Mathf.Sin(new_angle), 0f);        }        particleSystem.SetParticles(particlesArray, maxParticlesNum);    }}

0 0