How to render Compositing only by OpenGL? I do not use any object in my scene. All my Nodes are in the compositor, but when I render compositing by OpenGL I get only an empty screen.

I can use objects as simple trick, but I don't like that. I need output my compositing by opengl directly.

How can I render compositing by OpenGL only in blender?
- Using file node will use Blender Engine not Opengl
- When I press F12(Internal Blender engine) I see my compositing result.
- When I press Camera button(rendering by opengl ), I see nothing...empty viewport
That just not possible. OpenGL rendering only "saves" the current viewport content as an image. But when the only content created is in the Node Composit, that won't serve as a valid viewport content. Though there is a File Output Node for your Node Tree that you might use instead.