在 openGL 中渲染粒子的问题
Posted
技术标签:
【中文标题】在 openGL 中渲染粒子的问题【英文标题】：Problems rendering particles in openGL 【发布时间】：2012-11-22 23:00:50 【问题描述】：我开始使用 glut 在 OpenGL 中编写一个小粒子喷泉。我已经让粒子出现并在屏幕上反弹，就像我打算的那样。所以当我第一次运行程序时，我得到了这个
大约 2 秒后会变成这样
我试图弄乱代码以查看导致此问题的原因，但我无法解决它。
这是我目前在程序中所拥有的
int main() Init_particles() //初始化所有东西，在 main 中调用一次 无效激活粒子（）； //激活粒子 void Adjust_particle() //设置粒子的速度和弹跳void Render_particle() //渲染粒子，该函数在DrawGLScene()函数中调用。
void idle()//调用Adjust_particles和Activate_particles的空闲函数，后跟glutPostRedisplay()
这里是完整的代码：
// particle_fountain.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include<stdlib.h>
#include <stdio.h>
#include<Windows.h>
#include <time.h>
#include <GL\glut.h>
#include<GL\GLU.h>
#define MAX_PARTICLES 100
#define MAX_BOUNCE_COUNT 10
#define MAX_PARTICLE_AGE 50
//Colours
float R = 0.8f;
float G = 0.2f;
float B = 0.0f;
float cR = 0.001f;
float cG = 0.002f;
float cB = 0.003f;
float Size = 0.01f; //size for points
GLuint txParticle;
GLuint txPlane;
struct PARTICLE
float X,Y,Z; // Current position
float sX,sY,sZ; // Current Speed/Movement
float tX,tY,tZ; // Target Speed/Movement
float R,B,G; // Particle Colour
bool Active; // Is particle Active
int Age; // Age of the particle
int MaxAge; // Maximum Age before particle dies
int BounceCount;
Particles[MAX_PARTICLES];
void Init_Particles();
void Activate_Particles();
void Adjust_Particles();
void Render_Particles();
bool LoadBitmapTexture(char * FileName, GLuint &texid);
void idle();
void DrawGLscene();
void Reshape(GLsizei w, GLsizei h);
int main(int argc, char** argv)
glutInit(&argc,argv);
glutCreateWindow("Particle fountain");
Init_Particles();
glTranslatef(0.0f, -0.7f, 0.0f);
glutDisplayFunc(Render_Particles);
glutIdleFunc(idle);
glutMainLoop();
void idle()
Activate_Particles();
Adjust_Particles();
glutPostRedisplay();
void Init_Particles()
int p;
srand((int)time(NULL));
for(p=0; p<MAX_PARTICLES; p++)
Particles[p].Active = FALSE;
Particles[p].tX = 0.0f;
Particles[p].tY = -0.1f;
Particles[p].tZ = 0.0f;
void Activate_Particles()
int p;
for(p=0; p<MAX_PARTICLES; p++)
if(!Particles[p].Active)
// Start the particle at 0,0,0 origin
Particles[p].X = 0.0f;
Particles[p].Y = 0.0f;
Particles[p].Z = 0.0f;
// The following lines set a random speed value
Particles[p].sX = (((float)((rand() % 100) + 1)) /
1000.0f) - 0.05f;
Particles[p].sY = (((float)((rand() % 100) + 50)) /
500.0f);
Particles[p].sZ = (((float)((rand() % 100) + 1)) /
1000.0f) - 0.05f;
// We also activate the particle
Particles[p].Active = true;
// Set it's Age to zero
Particles[p].Age = 0;
// We also assign a max age to the particles
Particles[p].MaxAge = MAX_PARTICLE_AGE;
// We Also reset the bouncecount to zero
Particles[p].BounceCount = 0;
return;
void Adjust_Particles()
int p;
for(p=0; p<MAX_PARTICLES; p++)
// We move the speed towards the target speed by 1/20 (5%)
Particles[p].sX+= (Particles[p].tX - Particles[p].sX) / 20.0f;
Particles[p].sY+= (Particles[p].tY - Particles[p].sY) / 20.0f;
Particles[p].sZ+= (Particles[p].tZ - Particles[p].sZ) / 20.0f;
// Then we adjust the position of
// the particle by the new speed
Particles[p].X+= Particles[p].sX;
Particles[p].Y+= Particles[p].sY;
Particles[p].Z+= Particles[p].sZ;
// Now for the bounce code.
if(Particles[p].Y < 0.0f)
Particles[p].Y = 0.0f;
Particles[p].sY = -Particles[p].sY;
Particles[p].BounceCount++;
if(Particles[p].BounceCount > MAX_BOUNCE_COUNT)
Particles[p].Active = FALSE;
// And finally the age check
Particles[p].Age++;
if(Particles[p].Age > Particles[p].MaxAge)
Particles[p].Active = FALSE;
void Render_Particles()
int p;
glBegin(GL_POINTS);
for(p=0; p<MAX_PARTICLES; p++)
if(Particles[p].Active)
glColor4f(1.0f, 1.0f, 1.0f, 0.5f);
glVertex3f(Particles[p].X,
Particles[p].Y,
Particles[p].Z);
glEnd();
glFlush();
【问题讨论】：
【参考方案1】：在绘图前添加了 16 毫秒刷新和 glClear()：
// g++ main.cpp -o main -lglut -lGL
#include <GL/glut.h>
#define MAX_PARTICLES 100
#define MAX_BOUNCE_COUNT 10
#define MAX_PARTICLE_AGE 50
struct PARTICLE
float X,Y,Z; // Current position
float sX,sY,sZ; // Current Speed/Movement
float tX,tY,tZ; // Target Speed/Movement
float R,B,G; // Particle Colour
bool Active; // Is particle Active
int Age; // Age of the particle
int MaxAge; // Maximum Age before particle dies
int BounceCount;
Particles[MAX_PARTICLES];
void Init_Particles()
srand(0);
for(unsigned int p=0; p<MAX_PARTICLES; p++)
Particles[p].Active = false;
Particles[p].tX = 0.0f;
Particles[p].tY = -0.1f;
Particles[p].tZ = 0.0f;
void Activate_Particles()
for(unsigned int p=0; p<MAX_PARTICLES; p++)
if(!Particles[p].Active)
// Start the particle at 0,0,0 origin
Particles[p].X = 0.0f;
Particles[p].Y = 0.0f;
Particles[p].Z = 0.0f;
// The following lines set a random speed value
Particles[p].sX = (((float)((rand() % 100) + 1)) / 1000.0f) - 0.05f;
Particles[p].sY = (((float)((rand() % 100) + 50)) / 500.0f);
Particles[p].sZ = (((float)((rand() % 100) + 1)) / 1000.0f) - 0.05f;
// We also activate the particle
Particles[p].Active = true;
// Set it's Age to zero
Particles[p].Age = 0;
// We also assign a max age to the particles
Particles[p].MaxAge = MAX_PARTICLE_AGE;
// We Also reset the bouncecount to zero
Particles[p].BounceCount = 0;
return;
void Adjust_Particles()
for(unsigned int p=0; p<MAX_PARTICLES; p++)
// We move the speed towards the target speed by 1/20 (5%)
Particles[p].sX+= (Particles[p].tX - Particles[p].sX) / 20.0f;
Particles[p].sY+= (Particles[p].tY - Particles[p].sY) / 20.0f;
Particles[p].sZ+= (Particles[p].tZ - Particles[p].sZ) / 20.0f;
// Then we adjust the position of
// the particle by the new speed
Particles[p].X+= Particles[p].sX;
Particles[p].Y+= Particles[p].sY;
Particles[p].Z+= Particles[p].sZ;
// Now for the bounce code.
if(Particles[p].Y < 0.0f)
Particles[p].Y = 0.0f;
Particles[p].sY = -Particles[p].sY;
Particles[p].BounceCount++;
if(Particles[p].BounceCount > MAX_BOUNCE_COUNT)
Particles[p].Active = false;
// And finally the age check
Particles[p].Age++;
if(Particles[p].Age > Particles[p].MaxAge)
Particles[p].Active = false;
void Render_Particles()
Activate_Particles();
Adjust_Particles();
glClear( GL_COLOR_BUFFER_BIT );
glBegin(GL_POINTS);
for(unsigned int p=0; p<MAX_PARTICLES; p++)
if(Particles[p].Active)
glColor4f(1.0f, 1.0f, 1.0f, 0.5f);
glVertex3f(Particles[p].X, Particles[p].Y, Particles[p].Z);
glEnd();
glutSwapBuffers();
void timer(int extra)
glutPostRedisplay();
glutTimerFunc(16, timer, 0);
int main(int argc, char** argv)
glutInit(&argc,argv);
glutInitDisplayMode( GLUT_RGBA| GLUT_DOUBLE );
glutInitWindowSize( 640, 480 );
glutCreateWindow("Particle fountain");
Init_Particles();
glTranslatef(0.0f, -0.7f, 0.0f);
glutDisplayFunc(Render_Particles);
glutTimerFunc(0, timer, 0);
glutMainLoop();
【讨论】：
谢谢 :)，我尝试使用glClear()before，但是粒子移动得太快，我什么都看不见！，现在一切都很好！以上是关于在 openGL 中渲染粒子的问题的主要内容，如果未能解决你的问题，请参考以下文章
在 OpenGL 中将粒子渲染为具有透明度的 GL_TRIANGLE_FAN