I'm creating a hemispherical model using object graphics that is capable of being rotated, translated, zoomed, etc. When the window dimensions are square, the hemisphere is spherically shaped. I want the final aspect ratio to be 4:3 - when I implement this, the hemisphere becomes squashed. I tried to scale the model in the x-direction to look square again, but then the problem is that the trackball rotation from bottom left to top right makes changes the model from spherical to footballish. Does anyone know a way around this problem?