I’ve noticed a strange problem when clipping long lines w/ nvidia’s opengl drivers.
I’ve set up 3 lines to display my coordinate system. If I make these lines very long (ie. +/- 1000 world units so they’re bound to be clipped by the far plane), then … well, if I animate the rotation they jitter a lot by about +/-0.125 world units—which is a lot of screen space in my system. The lines do not jump if i shrink them to +/-10 world units – in fact, they line up properly all the time. A picture of the misalignment can be seen here:
(the blue lines are the axis lines: they should intersect at a point. ignore the grey lines;-)
does anyone know why this happens and how I can fix it? Incidentially, I notice the same kind of error with bzflag under my system: the ground plane jitters when I drive around.
Any ideas would be gratefully appreciated.
[This message has been edited by john (edited 03-17-2003).]