My goal is to define the cartographic limits for a geospatial query – something that many here have probably done already. When the horizon is not in view, a center-radius query may work, although returns outside of the inscribed screen field of view must be discarded. A bounding “rectangular” query has potential north-up issues. A polygon with more sampled screen edge points may be the best answer. But what is puzzling me right now is the best approach when the horizon is visible – ranging from the “home” camera position to any zoom that still retains some amount of visible horizon.
Do any examples demonstrate the best way to find the cartographic boundary points, including horizons? (while still permitting the user to tip the camera from orthographic to perspective)
Thanks for any example pointers.