rendering a scene with magnification
how is it done?
a few methods come to mind....
1. move everything x times closer to the camera, then render as usual. seems pretty easy, given position vector p0 = x,y,z from camera to object, and a magnification factor of m, new position is just p1 = (x/m,y/m,z/m) - right?
2. move the far plane x times farther out, and render everything at x times normal size. zbuf would be lower resolution, possibly leading to z fighting.
3. render to offscreen, then zoom by x amount. doesn't get stuff beyond the far plane that would be visible under magnification. doesn't get stuff within the viewing frustum that would be visible under magnification, but not visible without magnification.
what about the field of view? does that need to be adjusted? could FOV be used? i know narrow FOVs give a "scope" like effect....