My question might require some time with the paper, but I really need the answer.I''m currently trying to create a planet visualisation, and I need to render the part of the sphere as small as necessary. Surface is limited by 2 latitudes and longitudes, so I need to determine what are the optimal valuesof these 4 parameters so that the resulting piece includes all the points of the intersection of sphere(planet) and the cone(field of view),e.g.everything that should be visible is drawn, but not much time is wasted on the invisible part. Like if I''m 20-30 kms high above the planet, I don''t render the whole earth but rather put polygons into better detail. This is sphere description x=cos(long) * sin(lat) y=sin(long) * sin(lat) z=cos(lat)

It would have been preferable that you searched the forum archives before asking your question, since the answer is in there. You would not have had to wait 2 days for your answer in that case! The archive is a greeat resource that shouldn''t be overlooked.

Check out this thread...

Timkin