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Stuart McDonald
03-16-2008, 11:00 AM
Hi,
I'm rendering a skybox, but as the view changes e.g. turn left or right, it's obvious that's it's a cube i.e. you can tell where the corners are just because of the the change in perspective as it rotates.

I'm using gluPerspective with Y FoV=45, aspect=1.3 (800x600 screen). If I use a FoV of 33 (or widen the screen a lot) the effect is much less noticeable. I've read that people use a FoV of 90 (not sure if they mean X or Y, I assume X) but that gives a horrible fish eye.

I think I'm missing something fairly basic. Any pointers?

Cheers,

STU!

zeoverlord
03-16-2008, 12:21 PM
Fov in openGL is defined as the angle between center screen and one side, but in games like quake it refers to the angle between booth sides, so the fov 90 people claim to use is really fov 45.

Either way, if you have a skybox with equal sides, a good skybox texture, the camera in the direct center and a fov around 45 there should not be any distortions.
If you could take a screen shot where this is visible we might help you more.

Stuart McDonald
03-16-2008, 01:46 PM
So a YFoV of 33 with an aspect of 1.3 => X FoV =45 = 90 in quake etc. With that I don't get any distortion. What I had before is 120 FoV in quake terms, so it's just the fish-eye effect I'm getting (there were no other large objects at a distance, plus I had fog enabled so I've only noticed it with the skybox).

Thanks!