I am trying to record an animation from my Opengl 3D rendering code.
I save individual pictures using glReadPixels and assemble them later. My problem is that for each pictures I have to read in loads of data (astrophysical simulations) and the movie will be made of tousands of pictures: it takes hours to create. All runs smoothly if I let the Opengl window be open and more importantly on top of other windows on my screen. But since I want a 1000X1000 pixels movie, I can hardly work while the movie is being created. So my question is this,
How to force Opengl to compute the rendering in an hidden window?
I tried to use glReadBuffer(GL_BACK) but it looks like it updates the image only in the visible parts of the Opengl Window (I am on a Linux system, using X11)…
Any ideas? Or solutions?