C++ 如何使用粒子和更深的对象处理OpenGL加法混合和深度测试
我有一个用OpenGL和glut制作的小精灵粒子系统,使用纹理绘制基本火焰。火焰对称地再现,以说明它在小盒子/场景中的行为。如下图所示,存在两个问题: 1-为了产生一个看起来不错的火焰效果,我想使用添加剂混合我的粒子,但混合也考虑到更深的青色面板的颜色,并产生白色火焰 2.1-此外,为了实现添加剂混合的正确实施,我必须在绘制颗粒时禁用深度测试,但这样做可以绘制颗粒,即使它们应该“隐藏” 2.2-如果我在绘制粒子时启用深度测试,下面是它的外观 如果有帮助的话,下面是我应用到粒子上的纹理C++ 如何使用粒子和更深的对象处理OpenGL加法混合和深度测试,c++,c,opengl,shader,particle-system,C++,C,Opengl,Shader,Particle System,我有一个用OpenGL和glut制作的小精灵粒子系统,使用纹理绘制基本火焰。火焰对称地再现,以说明它在小盒子/场景中的行为。如下图所示,存在两个问题: 1-为了产生一个看起来不错的火焰效果,我想使用添加剂混合我的粒子,但混合也考虑到更深的青色面板的颜色,并产生白色火焰 2.1-此外,为了实现添加剂混合的正确实施,我必须在绘制颗粒时禁用深度测试,但这样做可以绘制颗粒,即使它们应该“隐藏” 2.2-如果我在绘制粒子时启用深度测试,下面是它的外观 如果有帮助的话,下面是我应用到粒子上的纹理 vo
void drawParticles()
{
glPushAttrib(GL_ALL_ATTRIB_BITS);
glDisable(GL_LIGHTING);
glDisable(GL_DEPTH_TEST);
glEnable(GL_TEXTURE_2D);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA,GL_ONE);
glBindTexture(GL_TEXTURE_2D,explosionTexture[0]);
glTexEnvi(GL_POINT_SPRITE, GL_COORD_REPLACE, GL_TRUE);
for (int i = 0; i < particlesNumber; ++i)
{
glPointSize(50.0f);
glBegin(GL_POINTS);
glColor4f(particlesArray[i].color[0],particlesArray[i].color[1],particlesArray[i].color[2],0.5f);
glVertex3f(particlesArray[i].position[0],particlesArray[i].position[1],particlesArray[i].position[2]);
glEnd();
}
glBindTexture(GL_TEXTURE_2D, 0);
glDisable( GL_BLEND );
glEnable( GL_DEPTH_TEST );
glPopAttrib();
}
void drawScene()
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective( 60.0f, (GLdouble) g_width / (GLdouble) g_height, 0.1f, 300.0f );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
gluLookAt( dist*sin(phi)*sin(theta), dist*cos(phi), dist*sin(phi)*cos(theta), 0, 0, 0, 0, 1, 0 );
glEnable( GL_DEPTH_TEST );
glDisable( GL_BLEND );
glBegin( GL_LINES );
glColor3f( 1.0f, 0.0f, 0.0f );
glVertex3f( 0.0f, 0.0f, 0.0f );
glVertex3f( 0.5f, 0.0f, 0.0f );
glColor3f( 0.0f, 1.0f, 0.0f );
glVertex3f( 0.0f, 0.0f, 0.0f );
glVertex3f( 0.0f, 0.5f, 0.0f );
glColor3f( 0.0f, 0.0f, 1.0f );
glVertex3f( 0.0f, 0.0f, 0.0f );
glVertex3f( 0.0f, 0.0f, 0.5f );
glEnd();
glBegin( GL_QUADS );
glColor4f( 1.0f, 1.0f, 1.0f , 0.0f);
glVertex3f( -1.0f, -0.2f, 1.0f );
glVertex3f( 1.0f, -0.2f, 1.0f );
glVertex3f( 1.0f, -0.2f, -1.0f );
glVertex3f( -1.0f, -0.2f, -1.0f );
glColor4f( 1.0f, 1.0f, 0.0f , 0.0f );
glVertex3f( 1.0f, -2.0f, 1.0f );
glVertex3f( 1.0f, -2.0f, -1.0f );
glVertex3f( 1.0f, -0.2f, -1.0f );
glVertex3f( 1.0f, -0.2f, 1.0f );
glColor4f( 1.0f, 0.0f, 1.0f , 0.0f );
glVertex3f( -1.0f, -2.0f, 1.0f );
glVertex3f( -1.0f, -2.0f, -1.0f );
glVertex3f( -1.0f, -0.2f, -1.0f );
glVertex3f( -1.0f, -0.2f, 1.0f );
glColor4f( 0.0f, 1.0f, 1.0f , 1.0f );
glVertex3f( 1.0f, -2.0f, -1.0f );
glVertex3f( -1.0f, -2.0f, -1.0f );
glVertex3f( -1.0f, -0.2f, -1.0f );
glVertex3f( 1.0f, -0.2f, -1.0f );
glEnd();
glPushMatrix();
drawParticles();
glScalef(1.0f, -1.0f, 1.0f);
drawParticles();
glPopMatrix();
glutSwapBuffers();
}
以下是显示场景和粒子的相关代码
void drawParticles()
{
glPushAttrib(GL_ALL_ATTRIB_BITS);
glDisable(GL_LIGHTING);
glDisable(GL_DEPTH_TEST);
glEnable(GL_TEXTURE_2D);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA,GL_ONE);
glBindTexture(GL_TEXTURE_2D,explosionTexture[0]);
glTexEnvi(GL_POINT_SPRITE, GL_COORD_REPLACE, GL_TRUE);
for (int i = 0; i < particlesNumber; ++i)
{
glPointSize(50.0f);
glBegin(GL_POINTS);
glColor4f(particlesArray[i].color[0],particlesArray[i].color[1],particlesArray[i].color[2],0.5f);
glVertex3f(particlesArray[i].position[0],particlesArray[i].position[1],particlesArray[i].position[2]);
glEnd();
}
glBindTexture(GL_TEXTURE_2D, 0);
glDisable( GL_BLEND );
glEnable( GL_DEPTH_TEST );
glPopAttrib();
}
void drawScene()
{
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
gluPerspective( 60.0f, (GLdouble) g_width / (GLdouble) g_height, 0.1f, 300.0f );
glMatrixMode( GL_MODELVIEW );
glLoadIdentity();
gluLookAt( dist*sin(phi)*sin(theta), dist*cos(phi), dist*sin(phi)*cos(theta), 0, 0, 0, 0, 1, 0 );
glEnable( GL_DEPTH_TEST );
glDisable( GL_BLEND );
glBegin( GL_LINES );
glColor3f( 1.0f, 0.0f, 0.0f );
glVertex3f( 0.0f, 0.0f, 0.0f );
glVertex3f( 0.5f, 0.0f, 0.0f );
glColor3f( 0.0f, 1.0f, 0.0f );
glVertex3f( 0.0f, 0.0f, 0.0f );
glVertex3f( 0.0f, 0.5f, 0.0f );
glColor3f( 0.0f, 0.0f, 1.0f );
glVertex3f( 0.0f, 0.0f, 0.0f );
glVertex3f( 0.0f, 0.0f, 0.5f );
glEnd();
glBegin( GL_QUADS );
glColor4f( 1.0f, 1.0f, 1.0f , 0.0f);
glVertex3f( -1.0f, -0.2f, 1.0f );
glVertex3f( 1.0f, -0.2f, 1.0f );
glVertex3f( 1.0f, -0.2f, -1.0f );
glVertex3f( -1.0f, -0.2f, -1.0f );
glColor4f( 1.0f, 1.0f, 0.0f , 0.0f );
glVertex3f( 1.0f, -2.0f, 1.0f );
glVertex3f( 1.0f, -2.0f, -1.0f );
glVertex3f( 1.0f, -0.2f, -1.0f );
glVertex3f( 1.0f, -0.2f, 1.0f );
glColor4f( 1.0f, 0.0f, 1.0f , 0.0f );
glVertex3f( -1.0f, -2.0f, 1.0f );
glVertex3f( -1.0f, -2.0f, -1.0f );
glVertex3f( -1.0f, -0.2f, -1.0f );
glVertex3f( -1.0f, -0.2f, 1.0f );
glColor4f( 0.0f, 1.0f, 1.0f , 1.0f );
glVertex3f( 1.0f, -2.0f, -1.0f );
glVertex3f( -1.0f, -2.0f, -1.0f );
glVertex3f( -1.0f, -0.2f, -1.0f );
glVertex3f( 1.0f, -0.2f, -1.0f );
glEnd();
glPushMatrix();
drawParticles();
glScalef(1.0f, -1.0f, 1.0f);
drawParticles();
glPopMatrix();
glutSwapBuffers();
}
void drawParticles()
{
glPushAttrib(GLU所有属性位);
glDisable(GLU照明);
glDisable(GLU深度测试);
glEnable(GL_纹理_2D);
glEnable(GL_混合物);
glBlendFunc(GL_SRC_ALPHA,GL_ONE);
glBindTexture(GL_TEXTURE_2D,explosionTexture[0]);
glTexEnvi(GL_POINT_SPRITE,GL_COORD_REPLACE,GL_TRUE);
for(int i=0;i
我愿意接受任何类型的建议,甚至包括着色器(但我想知道是否可以只使用普通OpenGL)
更新:
也许我不清楚,我不一定对严格固定的管道解决方案感兴趣,我想知道如何在场景中管理加法混合,即使这意味着将着色器代码添加到我的项目中
现在,正如Columbo指出的,启用深度测试和禁用深度写入解决了我的第二个问题。现在关于添加剂混合问题,我仍然不知道如何在场景中管理添加剂混合。尽管场景中可能没有这样的基本颜色,但问题仍然存在,因为火焰仍然是白色的,我愿意知道如何使用建议的像素着色器