I'm trying to make a world background by enclosing the whole area in a big sphere, and projecting a spherical map onto that sphere, as per a tutorial on youtube that I can't post because it won't let me post more than 2 links, but it's called "Blender Game Tutorial (2.6): Building a 3D Game - Part 1".
The sphere looks normal in the 3d viewport. Here it is with 3d display mode set to Solid, and inset in that image is with 3d display mode set to Material, showing that my image successfully mapped onto the sphere to make a space background to the world.
But when I go into active camera view (numpad 0), part of the sphere disappears!
The same thing happens when I render with F12 (I can't post more than two images though).
It does not seem to be an issue clipping/camera distance. I varied the max camera distance to quite a wide range of values, and it didn't affect this phenomenon at all.
I'm fairly new at Blender, thanks for any help you can give.

