FBO off-screen-rendering problem

To use depth test with FBOs, you have to attach a depth texture (or renderbuffer) first. In your PreparingGL_FBO method, create a texture using the DepthComponent internal format and attach it with:

GL.GenTextures(1, out depth_texture);
GL.BindTextures(TextureTarget.Texture2D, depth_texture);
GL.TexImage2D(TextureTarget.Texture2D, 0, PixelInternalFormat.DepthComponent, Width, Height, 0, OpenTK.Graphics.PixelFormat.DepthComponent, PixelType.UnsignedByte, IntPtr.Zero);
 
...
GL.FramebufferTexture2D(FramebufferTarget.Framebuffer, FramebufferAttachment.DepthAttachment, TextureTarget.Texture2D,texture, 0);

Afterwards, depth test should work as expected.

Edit: Some drivers need you to specify the exact bitdepth of the texture, e.g. PixelInternalFormat.DepthComponent24.

Yes, texture attachements is needed when you want to get rendered image (depth or color) as texture. If you don't, then use renderbuffer attachment.

Hi i am currently drawing offscreen to a renderbuffer attached to and FBO. I need to display the contents of the FBO back to "on-screen" i.e. the window. How can you do that without having to go to main memory by using the glreadpixels() and gldrawpixels()? If i should use glcopypixels() how can i do that because i am trying to get that working and only getting a blank screen back!

glBindFramebufferEXT(GL_READ_FRAMEBUFFER,bufferID);
glBindFramebufferEXT(GL_DRAW_FRAMEBUFFER,0);
glReadBuffer(GL_COLOR_ATTACHMENT0_EXT);
glDrawBuffer(GL_FRONT);
glRasterPos2d(0.0, 0.0);
glCopyPixels(0, 0, 500, 500, GL_COLOR);

Do i need to use renderbuffer for better performance or can i just use the texture, as with the latter averything is working fine?

so if the extension for blitting is not supported on the graphics card renderer then there is no other way i can do this pixel transfer?

i tried to use GL_BACK but still all i am getting are just artifacts (parts of the desktop current windows) rather than my drawing