我有一个相当复杂的场景,需要渲染许多 GL_POINTS。场景基本上是静态的,所以我想将它渲染到一个帧缓冲区对象,然后只在我的场景实际发生变化时更新该 FBO。然后我想在每一帧都将 FBO 渲染到屏幕上。
我找到了将 FBO 渲染为纹理的示例。我找到了将 FBO 渲染到 RenderBuffer 中的示例(仍然不太确定那是什么)。我不确定实现这一目标的步骤是什么。我是否需要渲染到纹理并将纹理绘制到屏幕上?
您能否列举将我的场景渲染到 FBO 然后将该 FBO 绘制到屏幕上的步骤(最好是伪代码或实际代码)。draw()
对于我自己的绘图功能来说,占位符就足够了。
最佳答案
我提供minimal FBO example就为了这个
基本上这些步骤是: 创建带有深度渲染缓冲区和颜色纹理附件的 FBO。要渲染到 FBO 取消绑定(bind)目标纹理,绑定(bind) FBO,渲染到 FBO。取消绑定(bind) FBO,绑定(bind)纹理,渲染。
#include <GL/glew.h>
#include <GL/glut.h>
#include <stdlib.h>
#include <stdio.h>
#include <math.h>
void init();
void display();
int const fbo_width = 512;
int const fbo_height = 512;
GLuint fb, color, depth;
int main(int argc, char *argv[])
{
glutInit(&argc, argv);
glutInitDisplayMode( GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH );
glutCreateWindow("FBO test");
glutDisplayFunc(display);
glutIdleFunc(glutPostRedisplay);
glewInit();
init();
glutMainLoop();
return 0;
}
void CHECK_FRAMEBUFFER_STATUS()
{
GLenum status;
status = glCheckFramebufferStatus(GL_DRAW_FRAMEBUFFER);
switch(status) {
case GL_FRAMEBUFFER_COMPLETE:
break;
case GL_FRAMEBUFFER_UNSUPPORTED:
/* choose different formats */
break;
default:
/* programming error; will fail on all hardware */
fputs("Framebuffer Error\n", stderr);
exit(-1);
}
}
float const light_dir[]={1,1,1,0};
float const light_color[]={1,0.95,0.9,1};
void init()
{
glGenFramebuffers(1, &fb);
glGenTextures(1, &color);
glGenRenderbuffers(1, &depth);
glBindFramebuffer(GL_FRAMEBUFFER, fb);
glBindTexture(GL_TEXTURE_2D, color);
glTexImage2D( GL_TEXTURE_2D,
0,
GL_RGBA,
fbo_width, fbo_height,
0,
GL_RGBA,
GL_UNSIGNED_BYTE,
NULL);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
glFramebufferTexture2D(GL_DRAW_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, color, 0);
glBindRenderbuffer(GL_RENDERBUFFER, depth);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, fbo_width, fbo_height);
glFramebufferRenderbuffer(GL_DRAW_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depth);
CHECK_FRAMEBUFFER_STATUS();
}
void prepare()
{
static float a=0, b=0, c=0;
glBindTexture(GL_TEXTURE_2D, 0);
glEnable(GL_TEXTURE_2D);
glBindFramebuffer(GL_FRAMEBUFFER, fb);
glViewport(0,0, fbo_width, fbo_height);
glClearColor(1,1,1,0);
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45, 1, 1, 10);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glEnable(GL_LIGHT0);
glEnable(GL_LIGHTING);
glEnable(GL_DEPTH_TEST);
glDisable(GL_CULL_FACE);
glLightfv(GL_LIGHT0, GL_POSITION, light_dir);
glLightfv(GL_LIGHT0, GL_DIFFUSE, light_color);
glTranslatef(0,0,-5);
glRotatef(a, 1, 0, 0);
glRotatef(b, 0, 1, 0);
glRotatef(c, 0, 0, 1);
glutSolidTeapot(0.75);
a=fmod(a+0.1, 360.);
b=fmod(b+0.5, 360.);
c=fmod(c+0.25, 360.);
}
void final()
{
static float a=0, b=0, c=0;
const int win_width = glutGet(GLUT_WINDOW_WIDTH);
const int win_height = glutGet(GLUT_WINDOW_HEIGHT);
const float aspect = (float)win_width/(float)win_height;
glBindFramebuffer(GL_FRAMEBUFFER, 0);
glViewport(0,0, win_width, win_height);
glClearColor(1.,1.,1.,0.);
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45, aspect, 1, 10);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glTranslatef(0,0,-5);
glRotatef(b, 0, 1, 0);
b=fmod(b+0.5, 360.);
glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, color);
glEnable(GL_DEPTH_TEST);
glEnable(GL_CULL_FACE);
glEnable(GL_BLEND);
glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glDisable(GL_LIGHTING);
float cube[][5]=
{
{-1, -1, -1, 0, 0},
{ 1, -1, -1, 1, 0},
{ 1, 1, -1, 1, 1},
{-1, 1, -1, 0, 1},
{-1, -1, 1, -1, 0},
{ 1, -1, 1, 0, 0},
{ 1, 1, 1, 0, 1},
{-1, 1, 1, -1, 1},
};
unsigned int faces[]=
{
0, 1, 2, 3,
1, 5, 6, 2,
5, 4, 7, 6,
4, 0, 3, 7,
3, 2, 6, 7,
4, 5, 1, 0
};
glEnableClientState(GL_VERTEX_ARRAY);
glEnableClientState(GL_TEXTURE_COORD_ARRAY);
glVertexPointer(3, GL_FLOAT, 5*sizeof(float), &cube[0][0]);
glTexCoordPointer(2, GL_FLOAT, 5*sizeof(float), &cube[0][3]);
glCullFace(GL_BACK);
glDrawElements(GL_QUADS, 24, GL_UNSIGNED_INT, faces);
glCullFace(GL_FRONT);
glDrawElements(GL_QUADS, 24, GL_UNSIGNED_INT, faces);
glDisableClientState(GL_VERTEX_ARRAY);
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
}
void display()
{
prepare();
final();
glutSwapBuffers();
}
关于opengl - 将我的场景渲染到帧缓冲区对象(FBO)然后将该 FBO 渲染到屏幕所需的步骤是什么?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/9742840/