Hi.
I want to do the following in OpenGL not with jMonkey.
I have jpg image 640x480. I want to draw that image so that it completely covers a 640x480 window. Then I want to draw 3d cube to whatever distance and I still want to have the cube drawn over the image. When the player moves around in 3D space then that image still covers entire window.
How can I do that? Can You point me somewhere?
why not in jme?
You should be able to draw a fullscreen Quad with your texture to get what you describe.
Draw your cube first, as normally you would, then call glDepthRange(1, 1) and draw a quad with extents (0,0) (1,1) in clip space.