Exporting Cycles Sky to skybox images I followed a tutorial Adding Clouds to Blender Cycles' Sky Texture on how to generate a nice sky in Blender with good  results.
Now I want to  export the sky as 6 images for making a skybox in my game engine (Esenthel). I tried with rotating the camera in the six directions needed( front, back, left, right, up and down) and saved the renders, but that didn't work to good as I got visible seams when applied in my engine skybox.

Do anyone have an advice on how to do this export correctly?
You can UVmap a cube and add a Glossy Material to it.  Set the Roughness parameter to 0.0
Add a Sub-Surface Modifier to the cube and set it to about 4 iterations, this helps for baking the Glossy Shader properly.

Add a texture node to the material so the sky can be baked to the UV Coordinates.



Now invert the faces for the cube so they face inwards. This should work as a SkyBox. 



If you want the sky to be available in a GLSL shader as a reflection map then you may want to pay closer attention to how the UV's are laid out since a game engine may have specific layout requirements for skybox/enviroment/cubeMaps.

Here's some reference on how to code a cubemap using a runtime technique that was published by nVidia, it uses nVidia CG which is a shader language that is compatible with both OpenGL and DirectX.  

https://web-beta.archive.org/web/20160408223256/http://http.developer.nvidia.com:80/CgTutorial/cg_tutorial_chapter07.html

And the source code to go along with the CgTutorial

https://developer.nvidia.com/cg-toolkit-download