我的问题是,在设置了一个帧缓冲区对象,其中单个颜色纹理附加到GL_COLOR_ATTACHMENT0点并将多个对象渲染到此纹理,然后我将其绘制到屏幕上,我得到一个完全白色的纹理
现在我知道绘图代码是正确的,因为我可以很好地绘制到后台缓冲区,只是当帧缓冲区涉及问题发生时。绘图代码使用一个非常基本的着色器来构造四边形。
我的代码如下:
// Create the FBO
glGenFramebuffers(1, &m_gbufferFBO);
glBindFramebuffer(GL_FRAMEBUFFER, m_gbufferFBO);
// Create a colour texture for use in the fbo
glGenTextures(1, &m_colourBuffer);
glBindTexture(GL_TEXTURE_2D, m_colourBuffer);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, m_width, m_height, 0, GL_RGBA, GL_UNSIGNED_BYTE, NULL);
glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, m_colourBuffer, 0);
// check if the frame buffer was successfully created
CheckFrameBufferErrors();
CheckGLErrors();
// Begin rendering with the frame buffer
glBindFramebuffer(GL_FRAMEBUFFER, m_gbufferFBO);
glPushAttrib(GL_VIEWPORT_BIT | GL_COLOR_BUFFER_BIT);
// Set the viewport to match the width and height of our FBO
glViewport(0, 0, m_width, m_height);
glDrawBuffer(GL_COLOR_ATTACHMENT0);
// Clear buffer to whatever the clear colour is set to
glClearColor(m_clearColour.GetR(), m_clearColour.GetG(), m_clearColour.GetB(), m_clearColour.GetA());
glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT );
Game::GetInstance().GetCamera()->ApplyViewTransform();
// RENDERING OF OBJECTS
glPopAttrib();
glBindFramebuffer(GL_FRAMEBUFFER, 0);
然后使用固定功能管道将缓冲区的颜色纹理渲染到屏幕上。
glDisable(GL_DEPTH_TEST);
glDisable(GL_BLEND);
glActiveTexture(GL_TEXTURE0);
glEnable(GL_TEXTURE_2D);
// Render the colour buffer to screen
glBindTexture(GL_TEXTURE_2D, m_colourBuffer);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
glBegin(GL_QUADS);
glTexCoord2f(0.f, 0.f); glVertex3f(0.f, 0.f, 0.f);
glTexCoord2f(1.f, 0.f); glVertex3f(m_width, 0.f, 0.f);
glTexCoord2f(1.f, 1.f); glVertex3f(m_width, m_height, 0.f);
glTexCoord2f(0.f, 1.f); glVertex3f(0.f, m_height, 0.f);
glEnd();
关于我在这里做错了什么的想法?
答案 0 :(得分:7)
绑定FBO时,不得绑定FBO附加纹理。纹理永远不会成为数据源并同时下沉。
对于纹理绑定到的所有纹理单元和目标,在将FBO绑定为渲染目标之前,必须绑定另一个或没有纹理。