Long time listener, first time caller says Hi!
I’ve been helped by this forum a lot over some time now, and before diving into my problem, would like to thank all those unsung heroes who’ve rescued me in the past; you know who you are
Now, my problem: what I basically would like to do is stretching my (horizontal) FOV angle to an arbitrarily wide value, say 320° for example. I do not wish for a fisheye effect (i.e., curvature of lines), but just a simple stretching of the viewing frustum.
Now as I understand it, it’s not possible to simply call glPerspective with a parameter set which would indicate such a FOV, since something like
glPerspective( 40.0, 320.0/40.0, <near>, <far> )
stretches my image, but cleary does not what I wand it to do, i.e., I don’t see the environment behind me.
So, question #1: Is there a way to just adapt basic viewing frustum setup steps to stretch the horizontal viewing frustum up to 320 degrees? As I don’t want a curvature effect, I would have assumed this to be possible…?
Next, my current plan of attack is to turn to framebuffer objects, similar to how cube maps are generated: render four different 80° views, and paste them together into a 320° image. Thus my second (possibly newbie-ish) question: how can I draw an FBO texture directly into the framebuffer? I don’t want to just ‘hang’ the FBO textures in front of the camera, but to directly paste the four FBO images into the framebuffer … which should be possible, given the right calls?
Cheers!