Unity3DGame学习笔记：粒子系统(homework9)

这次的任务是制作一个粒子光环

首先需要创建一个粒子系统，粒子系统参数设置如下

为了让粒子呈环状分布，我们需要设置其最大和最小半径，还需要设定粒子的数量

public int particleNum = 10000;public float minRadius = 7.0f;public float maxRadius = 10.0f;

通过两个float数组记录粒子所处的半径和角度，从而唯一确定某个粒子的位置

public float[] particleAngle;public float[] particleR;

下面这部分Start函数中的代码在实现粒子环状分布的同时，实现了粒子集中与环的中间而内圈及外圈的分布比较分散

for (int i = 0; i < particleNum; i++) {float midRadius = (maxRadius + minRadius)/2;float rate1 = Random.Range(1.0f, midRadius / minRadius);float rate2 = Random.Range(midRadius / maxRadius, 1.0f);particleR[i] = Random.Range(minRadius*rate1, maxRadius*rate2);particleAngle[i] = Random.Range(0.0f, 360.0f);float rad = particleAngle[i] / 180 * Mathf.PI;particleRing[i].position = new Vector3(particleR[i] * Mathf.Cos(rad), particleR[i] * Mathf.Sin(rad), 0.0f);}

除了初始化粒子的位置，还需要在Update函数中不断更新其位置使粒子动起来，通过索引将粒子分为两部分，第一部分顺时针移动，第二部分逆时针移动

for (int i = 0; i < particleNum; i++) {if (i % 2 == 0) {particleAngle [i] += (i % level + 1) * speed;} else {particleAngle [i] -= (i % level + 1) * speed;}particleAngle [i] = particleAngle [i] % 360;float rad = particleAngle [i] / 180 * Mathf.PI;particleRing [i].position = new Vector3 (particleR [i] * Mathf.Cos (rad), particleR [i] * Mathf.Sin (rad), 0.0f);}

目前实现效果如下：

要实现参考网站的光圈缩放效果，主要是要更改粒子分布的半径

在上面我们用float数组particleR[]储存每个粒子的半径，现在要实现缩小，要增加一个数组存放粒子在光圈缩小后的半径

还需要确定缩小后的最大最小半径

public float collectMinRadius = 6.0f;public float collectMaxRadius = 7.0f;public float[] collectParticleR;

用一个bool变量collect记录当前光圈的状态，在Update函数中，通过监听鼠标点击改变collect的值

通过collect的值重置粒子的位置

void Update() {if (Input.GetButtonDown ("fire1")) {Debug.Log ("mouse down!");if (collect == true) {collect = false;} else {collect = true;}}if (collect == false) {for (int i = 0; i < particleNum; i++) {if (i % 2 == 0) {particleAngle [i] += (i % level + 1) * speed;} else {particleAngle [i] -= (i % level + 1) * speed;}particleAngle [i] = particleAngle [i] % 360;float rad = particleAngle [i] / 180 * Mathf.PI;particleRing [i].position = new Vector3 (particleR [i] * Mathf.Cos (rad), particleR [i] * Mathf.Sin (rad), 0.0f);}} else {for (int i = 0; i < particleNum; i++) {if (i % 2 == 0) {particleAngle [i] += (i % level + 1) * speed;} else {particleAngle [i] -= (i % level + 1) * speed;}particleAngle [i] = particleAngle [i] % 360;float rad = particleAngle [i] / 180 * Mathf.PI;particleRing [i].position = new Vector3 (collectParticleR [i] * Mathf.Cos (rad), collectParticleR [i] * Mathf.Sin (rad), 0.0f);}}particleSystem.SetParticles (particleRing, particleNum);}

实现效果如下：

缩放效果是顺变的显得非常的突兀，因此我采用新的float数组记录当前的半径，在Update函数中与最终半径进行比较然后递增递减，从而实现缩放时渐变的效果

for (int i = 0; i < particleNum; i++) {if (collect == true) {if (currentR [i] > collectParticleR [i]) {currentR [i] -= (particleR [i] - collectParticleR [i]) / 50;}} else {if (currentR [i] < particleR [i]) {currentR[i] += (particleR [i] - collectParticleR [i]) / 50;}}if (i % 2 == 0) {particleAngle [i] += (i % level + 1) * speed;} else {particleAngle [i] -= (i % level + 1) * speed;}particleAngle [i] = particleAngle [i] % 360;float rad = particleAngle [i] / 180 * Mathf.PI;particleRing [i].position = new Vector3 (currentR [i] * Mathf.Cos (rad), currentR [i] * Mathf.Sin (rad), 0.0f);

}

最终实现效果如下：

下面是完整代码：

public class particle : MonoBehaviour {public ParticleSystem particleSystem;private ParticleSystem.Particle[] particleRing;public int particleNum = 10000;public float minRadius = 8.0f;public float maxRadius = 11.0f;public int level = 5;public float speed = 0.1f;public bool collect = false;public float collectMinRadius = 6.5f;public float collectMaxRadius = 8.0f;public float[] collectParticleR;public float[] particleAngle;public float[] particleR;public float[] currentR;void Start () {particleRing = new ParticleSystem.Particle[particleNum];particleSystem.maxParticles = particleNum;particleSystem.Emit(particleNum);particleSystem.GetParticles(particleRing);particleAngle = new float[particleNum];particleR = new float[particleNum];collectParticleR = new float[particleNum];currentR = new float[particleNum];for (int i = 0; i < particleNum; i++) {float midRadius = (maxRadius + minRadius)/2;float rate1 = Random.Range(1.0f, midRadius / minRadius);float rate2 = Random.Range(midRadius / maxRadius, 1.0f);particleR[i] = Random.Range(minRadius*rate1, maxRadius*rate2);particleAngle[i] = Random.Range(0.0f, 360.0f);float rad = particleAngle[i] / 180 * Mathf.PI;particleRing[i].position = new Vector3(particleR[i] * Mathf.Cos(rad), particleR[i] * Mathf.Sin(rad), 0.0f);float collectMidRadius = (collectMaxRadius + collectMinRadius) / 2;float rate3 = Random.Range(collectMinRadius / collectMaxRadius, 1.0f);collectParticleR[i] = Random.Range(collectMinRadius, collectMaxRadius * rate3);currentR [i] = particleR [i];}particleSystem.SetParticles(particleRing,particleNum);}void Update() {if (Input.GetButtonDown("Fire1")) {Debug.Log ("collect!");if (collect == true) {collect = false;} else {collect = true;}}for (int i = 0; i < particleNum; i++) {if (collect == true) {if (currentR [i] > collectParticleR [i]) {currentR [i] -= (particleR [i] - collectParticleR [i]) / 50;}} else {if (currentR [i] < particleR [i]) {currentR[i] += (particleR [i] - collectParticleR [i]) / 50;}}if (i % 2 == 0) {particleAngle [i] += (i % level + 1) * speed;} else {particleAngle [i] -= (i % level + 1) * speed;}particleAngle [i] = particleAngle [i] % 360;float rad = particleAngle [i] / 180 * Mathf.PI;particleRing [i].position = new Vector3 (currentR [i] * Mathf.Cos (rad), currentR [i] * Mathf.Sin (rad), 0.0f);}particleSystem.SetParticles (particleRing, particleNum);}}