I render to the individual faces of a cubemap by setting different views on the cubemap texture on the bound FBO.
After rendering is done I want to download the texture data using glGetTextureImageEXT.
I read somewhere that I should unbind the FBO before calling glGetTextureImageEXT. If I do that the first call to glGetTextureImageEXT works as expected, but the second call gives all zeros.
However, if I bind the FBO, set with the different texture views, before glGetTextureImageEXT, I get exactly the data I expect. The most confusing thing is, that it works a single time when no FBO is bound.
(I tried it with glGetTexImage and it behaves exactly the same.)
Any idea how this is supposed to behave?