Hello,
I wonder how I can change the plain color of my background to non-plain one Is it by a special function call ? …
Or using an image instead of color …
Where I can read/find a simple documentaions/tutorials showing this idea ?
… Thanks in advance for any help …
Hi !
It’s very easy, put a quad in the background, same size as the viewport and do what ever you want with it, color it or put a texture on it. (the faq on this website has information on how to map the window device coordinates to viewport coordinates using orthographic projection).
Just put it far away or disable depth buffer updates when you render it so that it doesn’t effect your depth test when you render the rest.
Mikael
YES … YES … YES … 
I draw a wonderful quad in my background …
Thank you very much mikael