多采样OpenGL FBO

Question

我正在尝试渲染3D场景到多采样FBO。我用下面的代码FBO创建FBO：

GLuint fbo, vtex, depthbuffer;
glGenTextures(1, &vtex); GLCHECK();
glBindTexture( vtarget, vtex ); GLCHECK();
glTexImage2DMultisample( GL_TEXTURE_2D_MULTISAMPLE, samples /*=4*/, GL_RGBA, width, height, false); GLCHECK();
glBindTexture(vtarget, 0); GLCHECK();

glGenRenderbuffers(1, &depthbuffer); GLCHECK();
glBindRenderbuffer(GL_RENDERBUFFER, depthbuffer); GLCHECK();
glRenderbufferStorageMultisample(GL_RENDERBUFFER, samples/*=4*/, GL_DEPTH_COMPONENT32, width, height); GLCHECK();
glBindRenderbuffer(GL_RENDERBUFFER, 0); GLCHECK();

glGenFramebuffers( 1, &fbo );GLCHECK();
glBindFramebuffer( GL_FRAMEBUFFER, fbo );GLCHECK();
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthbuffer); GLCHECK();
glFramebufferTexture2D( GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D_MULTISAMPLE, vtex, 0 ); GLCHECK();

if ((status = glCheckFramebufferStatus(GL_FRAMEBUFFER)) != GL_FRAMEBUFFER_COMPLETE)
{
    fprintf(stderr, "Can't allocate frame buffer! Status: 0x%x\n", status);
    assert(0);
}
glBindFramebuffer(GL_FRAMEBUFFER, 0); GLCHECK();

我得到了error GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE。我哪里做错了？

我已经阅读了this主题，FBO文档，但它没有帮助。

我可以在没有深度附加的情况下创建FBO。但在这种情况下，当我尝试将其显示在屏幕上时，它不起作用：

 glBindFramebuffer(GL_READ_FRAMEBUFFER, fbo); GLCHECK();
 glReadBuffer(GL_COLOR_ATTACHMENT0);

 glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0); GLCHECK();
 glDrawBuffer(GL_BACK); GLCHECK();

 glBlitFramebuffer(0, 0, resolution.width, resolution.height, 0, 0, resolution.width, resolution.height, GL_COLOR_BUFFER_BIT, GL_NEAREST); GLCHECK();

 glBindFramebuffer(GL_FRAMEBUFFER, 0);

请帮帮我。

Answer 1

您需要指定固定的采样位置。例如，glTexImage2DMultisample的最后一个参数为GL_TRUE。

您可以阅读有关GL_FRAMEBUFFER_INCOMPLETE_MULTISAMPLE here的原因。