使用正弦或余弦函数的 C/C++ 3D 烟花效果

I am trying to implement fireworks effect in C. I have a cube with dimensions 10x10x10. A rocket starts from the ground, and when it reaches 8th floor it explodes. Here's the point I cannot do - the explosion. How can I implement this using sine or cosine function?

所以在点(5,0,7) //(x,y,z)//火箭升空

for (j=0; j<9; j++) {
    setpoint(x, y, j);
    delay(100);
    clean();  //clears everything
}

爆炸的要点来了。如何实现这一目标？它也可以在随机位置闪闪发光。提前致谢。

呵呵，我确实找到了一些时间（在 1.5 Hod 中完成）并且愿意做这个有趣的事情:)

好的，首先在 LED_cube 类中进行一些更新以支持体素点输出并调暗其余部分与您的另一个问题中的球体相同......

//---------------------------------------------------------------------------
//--- LED cube class ver: 1.01 ----------------------------------------------
//---------------------------------------------------------------------------
#ifndef _LED_cube_h
#define _LED_cube_h
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
const int _LED_cube_size=32;
//---------------------------------------------------------------------------
class LED_cube
    {
public:
    int n,map[_LED_cube_size][_LED_cube_size][_LED_cube_size];

    LED_cube()              { n=_LED_cube_size; }
    LED_cube(LED_cube& a)   { *this=a; }
    ~LED_cube()             { }
    LED_cube* operator = (const LED_cube *a) { *this=*a; return this; }
    //LED_cube* operator = (const LED_cube &a) { /*...copy...*/ return this; }
    void cls(int col);                                  // clear cube with col 0x00BBGGRR
    void mul(int mul);                                  // mull all channels by mul and then shr by 8
    void point(int x,int y,int z,int col);              // draws voxel with col 0x00BBGGRR
    void sphere(int x0,int y0,int z0,int r,int col);    // draws sphere surface with col 0x00BBGGRR
    void glDraw();                                      // render cube by OpenGL as 1x1x1 cube at 0,0,0
    };
//---------------------------------------------------------------------------
void LED_cube::cls(int col)
    {
    int x,y,z;
    for (x=0;x<n;x++)
     for (y=0;y<n;y++)
      for (z=0;z<n;z++)
       map[x][y][z]=col;
    }
//---------------------------------------------------------------------------
void LED_cube::mul(int mul)
    {
    union { BYTE db[4]; int dd; } c;
    int x,y,z,i;
    for (x=0;x<n;x++)
     for (y=0;y<n;y++)
      for (z=0;z<n;z++)
        {
        c.dd=map[x][y][z];
        i=c.db[0]; i=(i*mul)>>8; c.db[0]=i;
        i=c.db[1]; i=(i*mul)>>8; c.db[1]=i;
        i=c.db[2]; i=(i*mul)>>8; c.db[2]=i;
        map[x][y][z]=c.dd;
        }
    }
//---------------------------------------------------------------------------
void LED_cube::point(int x,int y,int z,int col)
    {
    if ((x>=0)&&(x<n))
     if ((y>=0)&&(y<n))
      if ((z>=0)&&(z<n))
       map[x][y][z]=col;
    }
//---------------------------------------------------------------------------
void LED_cube::sphere(int x0,int y0,int z0,int r,int col)
    {
    int x,y,z,xa,ya,za,xb,yb,zb,xr,yr,zr,xx,yy,zz,rr=r*r;
    // bounding box
    xa=x0-r; if (xa<0) xa=0; xb=x0+r; if (xb>n) xb=n;
    ya=y0-r; if (ya<0) ya=0; yb=y0+r; if (yb>n) yb=n;
    za=z0-r; if (za<0) za=0; zb=z0+r; if (zb>n) zb=n;
    // project xy plane
    for (x=xa,xr=x-x0,xx=xr*xr;x<xb;x++,xr++,xx=xr*xr)
     for (y=ya,yr=y-y0,yy=yr*yr;y<yb;y++,yr++,yy=yr*yr)
        {
        zz=rr-xx-yy; if (zz<0) continue; zr=sqrt(zz);
        z=z0-zr; if ((z>0)&&(z<n)) map[x][y][z]=col;
        z=z0+zr; if ((z>0)&&(z<n)) map[x][y][z]=col;
        }
    // project xz plane
    for (x=xa,xr=x-x0,xx=xr*xr;x<xb;x++,xr++,xx=xr*xr)
     for (z=za,zr=z-z0,zz=zr*zr;z<zb;z++,zr++,zz=zr*zr)
        {
        yy=rr-xx-zz; if (yy<0) continue; yr=sqrt(yy);
        y=y0-yr; if ((y>0)&&(y<n)) map[x][y][z]=col;
        y=y0+yr; if ((y>0)&&(y<n)) map[x][y][z]=col;
        }
    // project yz plane
    for (y=ya,yr=y-y0,yy=yr*yr;y<yb;y++,yr++,yy=yr*yr)
     for (z=za,zr=z-z0,zz=zr*zr;z<zb;z++,zr++,zz=zr*zr)
        {
        xx=rr-zz-yy; if (xx<0) continue; xr=sqrt(xx);
        x=x0-xr; if ((x>0)&&(x<n)) map[x][y][z]=col;
        x=x0+xr; if ((x>0)&&(x<n)) map[x][y][z]=col;
        }
    }
//---------------------------------------------------------------------------
void LED_cube::glDraw()
    {
    #ifdef __gl_h_
    int x,y,z;
    float p[3],dp=1.0/float(n-1);
    glEnable(GL_BLEND);
    glBlendFunc(GL_ONE,GL_ONE);

    glPointSize(2.0);

    glBegin(GL_POINTS);

    for (p[0]=-0.5,x=0;x<n;x++,p[0]+=dp)
     for (p[1]=-0.5,y=0;y<n;y++,p[1]+=dp)
      for (p[2]=-0.5,z=0;z<n;z++,p[2]+=dp)
        {
        glColor4ubv((BYTE*)(&map[x][y][z]));
        glVertex3fv(p);
        }
    glEnd();
    glDisable(GL_BLEND);
    glPointSize(1.0);
    #endif
    }
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------
#endif
//---------------------------------------------------------------------------
//--------------------------------------------------------------------------

• 重要的是：
• void mul(int mul);- 用于调暗整个体素图
• void point(int x,int y,int z,int col);- 用于设置单个体素的颜色

现在的颗粒

//---------------------------------------------------------------------------
class particle
    {
public:
    double  x, y, z;    // position
    double vx,vy,vz;    // velocity
    double ax,ay,az;    // acceleration driving force/m after update is reseted
    double i;           // intensity
    particle()
        {
         x=0.0;  y=0.0;  z=0.0;
        vx=0.0; vy=0.0; vz=0.0;
        ax=0.0; ay=0.0; az=0.0;
        i=0.0;
        };
    particle(particle& a){ *this=a; };
    ~particle(){};
    particle* operator = (const particle *a) { *this=*a; return this; };
//  particle* operator = (const particle &a) { ...copy... return this; };

    void update(double dt)
        {
        double c0,c;
        // gravity
        ay-=9.81;
        // friction in gass
        c=0.001;
        if (vx>0.0) c0=-c; else c0=+c; ax+=vx*vx*c0;
        if (vy>0.0) c0=-c; else c0=+c; ay+=vy*vy*c0;
        if (vz>0.0) c0=-c; else c0=+c; az+=vz*vz*c0;
        // friction in liquid
        c=0.0;
        ax-=vx*vx*vx*c;
        ay-=vy*vy*vy*c;
        az-=vz*vz*vz*c;
        // D'ALembert
        vx+=ax*dt;
        vy+=ay*dt;
        vz+=az*dt;
         x+=vx*dt;
         y+=vy*dt;
         z+=vz*dt;
        // reset acceleration
        ax=0.0; ay=0.0; az=0.0;
        }
    };
//---------------------------------------------------------------------------
List<particle> particles; // use any list/array you have at your disposal you need just function add and delete item
//---------------------------------------------------------------------------

这是绘制场景的方法：

cube.mul(200);          // dimm the voxel map insted of clearing it  (intensity*=200/256)
for (int i=0;i<particles.num;i++)
    {
    particle *p=&particles[i];
    int j=double(255.0*p->i);
    if (j<0) j=0;
    if (j>255) j=255;
    cube.point(p->x,p->y,p->z,0x00010101*j);
    }
cube.glDraw();

这是如何更新某些计时器中的模拟（双倍 dt=以秒为单位的计时器间隔！！！）

double i0=1.0; // intensity at shoot start
double i1=0.9*i0; // intensity after explosion
double v0=0.6*double(_LED_cube_size); // shoot start speed
double v1=0.5*v0,v1h=0.5*v1; // explosion speed
if (particles.num==0) // shoot new particle if none in list
    {
    particle p;
    p.x=_LED_cube_size>>1;
    p.y=0.0;
    p.z=_LED_cube_size>>1;
    p.vy=v0;
    p.i=i0;
    particles.add(p);
    }
for (int i=0;i<particles.num;i++) // update all particles in list
    {
    particle *p=&particles[i];
    p->update(dt);
    if (fabs(p->i-i0)<1e-6)     // intensity detect state before explosion
        {
        if (p->vy<=0.0)         // explode near/after peak reached
            {
            particle q;
            q.x=p->x;               // copy position
            q.y=p->y;
            q.z=p->z;
            q.i=i1;                 // new intensity
            particles.del(i);       // remove old particle
            i--;
            for (int j=0;j<50;j++)  // add new random particles
                {
                q.vx=v1*Random()-v1h;
                q.vy=v1*Random()-v1h;
                q.vz=v1*Random()-v1h;
                particles.add(q)-v1h;
                }
            continue;               // avoid usage of p pointer after delete
            }
        }
    else{                       // after explosion
        p->i*=0.95;             // dimm intensity
        }
    if ((p->y<0.0)||(p->i<0.01))// remove particles below the ground or too dimmed out
        {
        particles.del(i);
        i--;
        continue;               // avoid usage of p pointer after delete
        }
    }

这就是它的样子

对不起，横幅，但我没有任何可靠的 gif 转换，并且该网站不接受 wmv ...您必须使用常量来匹配 LED 立方体大小常量上所需的输出：

1. 整个立方体贴图调光率 (cube.mul(200)) 当前每帧 (200/256)
2. 速度、强度v0,v1,i0,i1
3. 目前爆炸后新粒子数量为 50
4. 爆炸后粒子强度调暗率目前为0.95

[Notes]

List<>只是动态数组的模板可以使用以下任何内容std::或者自己的数组...

不要忘记设置dt更新之间经过的时间常数。希望我没有忘记复制一些东西。希望能帮助到你